On the great importance of believing and practicing the infallible teaching of the Catholic Church, "the voice of God on earth", FOR LOVE OF GOD

"And the Lord said to Moses: How long will you refuse to keep My commandments, and My law?" (Exodus 16, 28)

"Every soul that shall commit any of these abominations [see verses 1-28], shall perish from the midst of his people. Keep My commandments. Do not the things which they have done, that have been before you, and be not defiled therein. I am the Lord your God." (Leviticus 18, 29-30)

"My son, forget not My law, and let thy heart keep My Commandments. For they shall add to thee length of days, and years of life and peace. Let not mercy and truth leave thee, put them about thy neck, and write them in the tables of thy heart: And thou shalt and grace and good understanding before God and men." (Proverbs 3, 1-4)

"If you love Me, keep My commandments." (John 14, 15)

"He that hath My commandments, and keepeth them; he it is that loveth Me. And he that loveth Me, shall be loved of My Father: and I will love him, and will manifest myself to him." (Ibid., 14, 21)

"Jesus answered, and said to him: If any one love Me, he will keep My word, and my Father will love him, and We will come to him, and will make our abode with him." (Ibid., 14, 23)

"He that loveth Me not, keepeth not My words. And the word which you have heard, is not mine; but the Father's who sent Me." (Ibid., 14, 24)

"As the Father hath loved Me, I also have loved you. Abide in My love. If you keep My commandments, you shall abide in My love; as I also have kept My Father's commandments, and do abide in His love. These things I have spoken to you, that My joy may be in you, and your joy may be filled." (John 15, 9-11)

"He that heareth you [the Church], heareth Me; and he that despiseth you, despiseth Me; and he that despiseth Me, despiseth Him that sent Me." (Luke 10, 16)

"And if he will not hear the Church, let him be to thee as the heathen and publican." (Matthew 18, 17)

« 10. This consideration too clarifies the great error of those others as well who boldly venture to explain and interpret the words of God by their own judgment, misusing their reason and holding the opinion that these words are like a human work. God Himself has set up a living authority to establish and teach the true and legitimate meaning of His heavenly revelation. This authority judges infallibly all disputes which concern matters of faith and morals, lest the faithful be swirled around by every wind of doctrine which springs from the evilness of men in encompassing error. And this living infallible authority is active only in that Church which was built by Christ the Lord upon Peter, the head of the entire Church, leader and shepherd, whose faith He promised would never fail. This Church has had an unbroken line of succession from Peter himself; these legitimate pontiffs are the heirs and defenders of the same teaching, rank, office and power. And the Church is where Peter is, [St. Ambrose on Ps 40.] and Peter speaks in the Roman Pontiff, [Council of Chalcedon, Act. 2.] living at all times in his successors and making judgment,[Synod of Ephes., Act. 3.] providing the truth of the faith to those who seek it. [St. Peter Chrysologus, epistle to Eutyches.] The divine words therefore mean what this Roman See of the most blessed Peter holds and has held.

« 11. For this mother and teacher [Council of Trent, session 7 on baptism.] of all the churches has always preserved entire and unharmed the faith entrusted to it by Christ the Lord. Furthermore, it has taught it to the faithful, showing all men truth and the path of salvation. Since all priesthood originates in this church, [St. Cyprian, epistle 55 to Pope Cornelius.] the entire substance of the Christian religion resides there also. [Synod. Letter of John of Constantinople to Pope Hormisdas and Sozomen, Hist., III. 8.] The leadership of the Apostolic See has always been active, [St. Augustine, epistle 162.] and therefore because of its preeminent authority, the whole Church must agree with it. The faithful who live in every place constitute the whole Church. [St. Irenaeus, Adv. Haer. III, 3.] Whoever does not gather with this Church scatters. [St. Jerome, epistle to Pope Damasus.]

« 12. We, therefore, placed inscrutably by God upon this Chair of truth, eagerly call forth in the Lord your outstanding piety, venerable brothers. We urge you to strive carefully and zealously to continually warn and exhort the faithful entrusted to your care to hold to these first principles. Urge them never to allow themselves to be deceived and led into error by men who have become abominable in their pursuits. These men attempt to destroy faith on the pretext of human progress, subjecting it in an impious manner to reason and changing the meaning of the words of God. Such men do not shrink from the greatest insults to God Himself, who cares for the good and the salvation of men by means of His heavenly religion. » (HH Pope Pius IX, "Qui Pluribus", 9 November 1846)

« If in the difficult times in which Our lot is cast, Catholics will give ear to Us, as it behoves them to do, they will readily see what are the duties of each one in matters of opinion as well as action. As regards opinion, whatever the Roman Pontiffs have hitherto taught, or shall hereafter teach, must be held with a firm grasp of mind, and, so often as occasion requires, must be openly professed. » (HH Pope Leo XIII, "Immortale Dei", 1 November 1885)

« 19 Q. Where are the truths which God has revealed contained?

A. The truths which God has revealed are contained in Holy Scripture and in 

Tradition.

« 31 Q. Are we obliged to believe all the truths the Church teaches us? 

« A. Yes, we are obliged to believe all the truths the Church teaches us, and Jesus Christ declares that he who does not believe is already condemned. 

« 32 Q. Are we also obliged to do all that the Church commands? 

« A. Yes, we are obliged to do all that the Church commands, for Jesus Christ has said to the Pastors of the Church: "He who hears you, hears Me, and he who despises you, despises Me." 

« 33 Q. Can the Church err in what she proposes for our belief? 

« A. No, the Church cannot err in what she proposes for our belief, since according to the promise of Jesus Christ she is unfailingly assisted by the Holy Ghost. 

« 34 Q. Is the Catholic Church infallible, then? 

« A. Yes, the Catholic Church is infallible, and hence those who reject her definitions lose the faith and become heretics. 

« 35 Q. Can the Catholic Church be destroyed or perish? 

« A. No; the Catholic Church may be persecuted, but she can never be destroyed or perish. She will last till the end of the world, because Jesus Christ, as He promised, will be with her till the end of time.

[...] « 46 Q. Are we obliged to hear the Teaching Church? 

« A. Yes, without doubt we are obliged under pain of eternal damnation to hear the Teaching Church; for Jesus Christ has said to the Pastors of His Church, in the persons of the Apostles: "He who hears you, hears Me, and he who despises you, despises Me."

[...] « 55 Q. Can the Pope err when teaching the Church? 

« A. The Pope cannot err, that is, he is infallible, in definitions regarding faith and morals. 

« 56 Q. How is it that the Pope is infallible? 

« A. The Pope is infallible because of the promise of Jesus Christ, and of the unfailing assistance of the Holy Ghost. » (From the Catechism of Pope saint Pius X, 1905)

“To the shepherds alone was given all power to teach, to judge, to direct; on the faithful was imposed the duty of following their teaching, of submitting with docility to their judgment, and of allowing themselves to be governed, corrected, and guided by them in the way of salvation. Thus, it is an absolute necessity for the simple faithful to submit in mind and heart to their own pastors, and for the latter to submit with them to the Head and Supreme Pastor.” (HH Pope Leo XIII, Letter "Epistola Tua" to Cardinal Guibert, June 17, 1885; excerpted in Papal Teachings: The Church, p. 263)

"". . . JESUS-CHRIST sent His Apostles into the whole world in order that they might permeate all nations with the Gospel faith, and, lest they should err, He willed beforehand that they should be taught by the Holy Ghost: has then this doctrine of the Apostles completely vanished away, or SOMETIMES been obscured, in the Church, whose ruler and defense is God Himself? If our Redeemer plainly said that His Gospel was to continue not only during the times of the Apostles, but also till future ages, is it possible that the object of faith should in the process of time become so obscure and uncertain, that it would be necessary to-day to tolerate opinions which are even incompatible one with another? If this were true, we should have to confess that the coming of the HOLY GHOST on the Apostles, and the perpetual indwelling of the same Spirit in the Church, and the very preaching of JESUS-CHRIST, have several centuries ago, lost all their efficacy and use, to affirm which would be BLASPHEMY. But the Only-begotten Son of God, when He commanded His representatives to teach all nations, obliged all men to give credence to WHATEVER was made known to them by "witnesses preordained by God," [Acts X, 41] and also confirmed His command with this sanction: "He that believeth and is baptized shall be saved; but he that believeth not shall be condemned." [Mark XVI, 16] These two commands of CHRIST, which must be fulfilled, the one, namely, to teach, and the other to believe, cannot even be understood, unless the Church proposes a complete and easily understood teaching, and is IMMUNE when it thus teaches from ALL DANGER OF ERRING." (HH the Pope Pius XI, "Mortalium Animos", 1928)

"Our Lord JESUS-CHRIST, the Son of God, and Redeemer of mankind, before returning to His Heavenly Father, promised that He would be with the Church Militant on earth all days, even to the consummation of the world. Therefore He has never ceased to be present with His beloved Spouse, to assist her when teaching, to bless her when at work, and to aid her when in danger. . . Hence the Catholic Church CAN NEVER forbear from witnessing to and proclaiming the truth of God, which heals all things, knowing the words addressed to it: "My Spirit that is in thee, and My words that I have put in thy mouth, shall not depart out of thy mouth, from henceforth and for ever. (Isa. LIX, 21)" (Vatican Council I, Dogmatic Constitution "Dei Filius")

"Nor can we pass over in silence the audacity of those who, not enduring sound doctrine, contend that "without sin and without any sacrifice of the Catholic profession assent and obedience may be refused to those judgments and decrees of the Apostolic See, whose object is declared to concern the Church's general good and her rights and discipline, so only it does not touch the dogmata of faith and morals." But no one can be found not clearly and distinctly to see and understand how grievously this is opposed to the Catholic dogma of the full power given from God by Christ our Lord Himself to the Roman Pontiff of feeding, ruling and guiding the Universal Church." (His Holiness Pope Pius IX, "Quanta Cura", 8 December 1864)

"Assuming false and unjust premises, they are not afraid to take a position which would confine within a NARROW SCOPE the Supreme Teaching Authority of the Church, claiming that there are certain questions -- such as those which concern social and economic matters -- in which Catholics may ignore the teachings and the directives of this Apostolic See. 

"This opinion -- it seems entirely unnecessary to demonstrate its existence -- is utterly FALSE and FULL OF ERROR because, as We declared a few years ago to a special meeting of Our Venerable Brethren in the episcopacy: 

"'The power of the Church is IN NO SENSE limited to so-called 'strictly religious matters'; but the whole matter of the natural law, its institution, interpretation and application, in so far as the moral aspect is concerned, are within its power. 

"'By God's appointment the observance of the natural law concerns the way by which man must strive toward his supernatural end. The Church shows the way and is the guide and guardian of men with respect to their supernatural end.' 

"This truth had already been wisely explained by Our Predecessor St. Pius X in his Encyclical Letter 'Singulari quadam' of September 24, 1912, in which he made this statement: 'ALL ACTIONS of a Christian man so far as they are morally either good or bad -- that is, so far as they agree with or are contrary to the natural and divine law -- fall under the judgment and jurisdiction of the Church.'

"Moreover, even when those who arbitrarily set and defend these narrow limits profess a desire to obey the Roman Pontiff with regard to truths to be believed, and to observe what they call ecclesiastical directives, they proceed with such boldness that they refuse to obey the precise and definite prescriptions of the Holy See. They protest that these refer to POLITICAL affairs because of a hidden meaning by the author, as if these prescriptions took their origin from some secret conspiracy against their own nation." (HH the Pope Pius XII, "Ad Apostolorum Principis", 29 June 1958)

"Amid such reckless and widespread folly of opinion, it is, as We have said, the office of the Church to undertake the defense of truth and uproot errors from the mind, and this charge has to be at all times sacredly observed by her, seeing that the honor of God and the salvation of men are confided to her keeping. But, when necessity compels, not those only who are invested with power of rule are bound to safeguard the integrity of faith, but, as St. Thomas maintains: "Each one is under obligation to show forth his faith, either to instruct and encourage others of the faithful, or to repel the attacks of unbelievers." 

". . . It happens far otherwise with Christians; they receive their rule of faith from the Church, by whose authority and under whose guidance they are conscious that they have beyond question attained to truth. Consequently, as the Church is one, because Jesus Christ is one, so throughout the whole Christian world there is, and ought to be, but one doctrine: "One Lord, one faith;" "but having the same spirit of faith," they possess the saving principle whence proceed spontaneously one and the same will in all, and one and the same tenor of action.

"Now, as the Apostle Paul urges, this unanimity [in obedience] ought to be perfect. Christian faith reposes not on human but on divine authority, for what God has revealed "we believe not on account of the intrinsic evidence of the truth perceived by the natural light of our reason, but on account of the authority of God revealing, who cannot be deceived nor Himself deceive." It follows as a consequence that whatever things are manifestly revealed by God we must receive with a similar and equal assent. To refuse to believe any one of them is equivalent to rejecting them all, for those at once destroy the very groundwork of faith who deny that God has spoken to men, or who bring into doubt His infinite truth and wisdom. 

"To determine, however, which are the doctrines divinely revealed belongs to the teaching Church, to whom God has entrusted the safekeeping and interpretation of His utterances. But the supreme teacher in the Church is the Roman Pontiff. Union of minds, therefore, requires, together with a perfect accord in the one faith, COMPLETE SUBMISSION and OBEDIENCE of will to the Church and to the Roman Pontiff, as to God Himself. This obedience should, however, be perfect, because it is enjoined by faith itself, and has this in common with faith, that it cannot be given in shreds; nay, were it not absolute and perfect in every particular, it might wear the name of obedience, but its essence would disappear. Christian usage attaches such value to this perfection of obedience that it has been, and will ever be, accounted the distinguishing mark by which we are able to recognize Catholics. 

"Admirably does the following passage from St. Thomas Aquinas set before us the right view: "The formal object of faith is primary truth, as it is shown forth in the holy Scriptures, and in the teaching of the Church, which proceeds from the fountainhead of truth. It follows, therefore, that he who does not adhere, as to an infallible divine rule, to the teaching of the Church, which proceeds from the primary truth manifested in the Holy Scriptures, possesses not the habit of faith; but matters of faith he holds otherwise than true faith. Now, it is evident that he who clings to the doctrines of the Church as to an infallible rule yields his assent to EVERYTHING the Church teaches; but otherwise, if with reference to what the Church teaches he holds what he likes but does not hold what he does not like, he adheres not to the teaching of the Church as to an infallible rule, but to his own will."

""The faith of the whole Church should be one, according to the precept (1 Cor. 1:10): "Let all speak the same thing, and let there be no schisms among you"; and this cannot be observed save on condition that questions which arise touching faith should be determined by him who presides over the whole Church, whose sentence must consequently be accepted without wavering. And hence to the sole authority of the supreme Pontiff does it pertain to publish a new revision of the symbol, as also to decree all other matters that concern the universal Church."

"In defining the limits of the obedience owed to the pastors of souls, but most of all to the authority of the Roman Pontiff, it must NOT be supposed that it is ONLY to be yielded in relation to dogmas of which the obstinate denial cannot be disjoined from the crime of heresy. Nay, further, it is not enough sincerely and firmly to assent to doctrines which, though not defined by any solemn pronouncement of the Church, are by her proposed to belief, as divinely revealed, in her common (ordinary) and universal teaching, and which the Vatican Council declared are to be believed "with Catholic and divine faith." BUT this likewise must be reckoned amongst the duties of Christians, that they allow themselves to be RULED and DIRECTED by the authority and leadership of bishops, and, above all, of the Apostolic See. And how fitting it is that this should be so any one can easily perceive. For the things contained in the divine oracles have reference to God in part, and in part to man, and to whatever is necessary for the attainment of his eternal salvation. Now, both these, that is to say, what we are bound to believe and what we are obliged to do, are laid down, as we have stated, by the Church using her divine right, and in the Church by the supreme Pontiff. Wherefore it belongs to the Pope to judge authoritatively what things the sacred oracles contain, as well as what doctrines are in harmony, and what in disagreement, with them; and also, for the same reason, to show forth what things are to be accepted as right, and what to be rejected as worthless; what it is necessary to do and what to avoid doing, in order to attain eternal salvation. For, otherwise, there would be no sure interpreter of the commands of God, nor would there be any safe guide showing man the way he should live." (HH Pope Leo XIII, Sapientiae Christianae, 10 January 1890)