I charge you in the presence of God and of Christ Jesus, who will judge the living and the dead, and by his appearing and his kingly power: proclaim the word; be persistent whether it is convenient or inconvenient; convince, reprimand, encourage through all patience and teaching. For the time will come when people will not tolerate sound doctrine but, following their own desires and insatiable curiosity, will accumulate teachers and will stop listening to the truth and will be diverted to myths. But you, be self-possessed in all circumstances; put up with hardship; perform the work of an evangelist; fulfill your ministry. (2 Tim 4:1-5)

But see whence He begins, and whence He aggravates His blame of them. For they say, He says, and do not. For every one is worthy of blame in transgressing the law, but especially he that bears the authority of teaching, for doubly and triply does he deserve to be condemned. For one cause, because he transgresses; for another, that as he ought to amend others, and then halts, he is worthy of a double punishment, because of his dignity; and in the third place, that he even corrupts the more, as committing such transgression in a teacher’s place. (Saint John Chrysostom, Homily LXXII on St. Matthew, no. 72)

Now, if we cannot expect to reap a harvest when no seed has been planted, how can we hope to have a people with sound morals if Christian doctrine has not been imparted to them in due time? It follows, too, that if faith languishes in our days, if among large numbers it has almost vanished, the reason is that the duty of catechetical teaching is either fulfilled very superficially or altogether neglected. (Pius X. Encyclical Acerbo Nimis, no. 16, April 15, 1905)

Hence, the graver the evils threatening the flock, the greater the solicitude the Roman Pontiffs ought to employ in preventing them. For, those who have been placed in the topmost Watch Tower of the Church can discern from afar the artifices which the enemies of the Christian family undertake to destroy the Church of Christ: (which they will never achieve) they can point them out and expose them to the faithful, who may then guard against them; they can drive away and remove them by their Authority.  (Leo XII, Apostolic Constitution Quo Graviora, no. 1, March 13, 1826)

Admonish and exhort them to be strong in our sacred faith, without which it is impossible to please God. Urge them to persevere firmly established in our divine religion, which alone is true and eternal and prepares for salvation and even, to a very great extent, preserves and prospers civil society. Through the parish priests chiefly and other ecclesiastics known for integrity of life, gravity of morals, and constant adherence to sound doctrine, may you teach unremittingly and accurately: at one time preaching the divine word, at another instructing the people in the mysteries of our august religion, its doctrine, precepts, and discipline. You, above all, know that many evils generally arise from ignorance of divine matters essential for salvation. Hence, you will understand that it behooves you to use every care and diligence that so detrimental a condition be prevented.  (Pius IX. Encyclical Quanto Conficiamur, nos. 13-14, August 10, 1863)

Further, the Church which, together with the apostolic duty of teaching, has received the command to guard the deposit of faith, has also, from divine Providence, the right and duty of proscribing ‘knowledge falsely so called’ (1Tim 6:20), ‘lest anyone be cheated by philosophy and vain deceit’ (cf. Col 2:8). (Denzinger-Hünermann 3018. Vatican Council I, Dogmatic Constitution Dei Filius, April 24, 1870)

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’ (STh II-II q.3, a.2, ad 2). To recoil before an enemy, or to keep silence when from all sides such clamors are raised against truth, is the part of a man either devoid of character or who entertains doubt as to the truth of what he professes to believe. In both cases such mode of behaving is base and is insulting to God, and both are incompatible with the salvation of mankind. This kind of conduct is profitable only to the enemies of the faith, for nothing emboldens the wicked so greatly as the lack of courage on the part of the good. (Leo XIII. Encyclical Sapientiae Christianae, no. 14, January 10, 1890)

Yet, if there is hope of profit to the faith, or if there be urgency, a man should disregard the disturbance of unbelievers, and confess his faith in public. Hence it is written (Mt 15:12) that when the disciples had said to Our Lord that ‘the Pharisee, when they heard this word, were scandalized,’ He answered: ‘Let them alone, they are blind, and leaders of the blind.’ (Saint Thomas Aquinas, Summa Theologica II-II, q. 3, a. 2, ad 3)

Evidently, this is true for all the baptized, yet it is especially incumbent upon those who, by virtue of their social or political position, must make decisions regarding fundamental values, such as respect for human life, its defence from conception to natural death, the family built upon marriage between a man and a woman, the freedom to educate one’s children and the promotion of the common good in all its forms (Cf. John Paul II, Encyclical Evangelium Vitae: AAS 87(1995),401-522; Benedict XVI, Address to the Pontifical Academy for Life – 27 February 2006: AAS 98(2006), 264-265). These values are not negotiable. Consequently, Catholic politicians and legislators, conscious of their grave responsibility before society, must feel particularly bound, on the basis of a properly formed conscience, to introduce and support laws inspired by values grounded in human nature (Cf. Cong. for the Doct.of the Faith, Doctrinal note on questions regarding participation of Catholics in political life: AAS 96(2004),359-370). There is an objective connection here with the Eucharist (cf. 1Cor 11:27-29). Bishops are bound to reaffirm constantly these values as part of their responsibility to the flock entrusted to them (cf. Propositio 46). (Benedict XVI. Post-Synodal Apostolic Exhortation Sacramentum Caritatis, no. 83, February 22, 2007)

For bishops are preachers of the faith, who lead new disciples to Christ, and they are authentic teachers, that is, teachers endowed with the authority of Christ, who preach to the people committed to them the faith they must believe and put into practice, and by the light of the Holy Spirit illustrate that faith. They bring forth from the treasury of Revelation new things and old (Mt 13:52), making it bear fruit and vigilantly warding off any errors that threaten their flock (2Tim 4:1-4). (Vatican Council II, Dogmatic Constitution Lumen Gentium, no. 25, November 21, 1964)

For the Church is, by the will of Christ, the teacher of the truth. It is her duty to give utterance to, and authoritatively to teach, that truth which is Christ Himself, and also to declare and confirm by her authority those principles of the moral order which have their origins in human nature itself. (Vatican Council II, Declaration Dignitatis Humanae, no. 14, December 7,  1965)

But we wish to make it clear that departure from the Church’s teaching, or silence about it, in an effort to provide pastoral care is neither caring nor pastoral. Only what is true can ultimately be pastoral. The neglect of the Church’s position prevents homosexual men and women from receiving the care they need and deserve. (Congregation for the Doctrine of the Faith, Letter to the Bishops of the Catholic Church on the pastoral care of homosexual persons, no. 15, October 1, 1986)

We recognize, of course, that in great measure the clear and successful communication of the Church’s teaching to all the faithful, and to society at large, depends on the correct instruction and fidelity of her pastoral ministers. The Bishops have the particularly grave responsibility to see to it that their assistants in the ministry, above all the priests, are rightly informed and personally disposed to bring the teaching of the Church in its integrity to everyone. (Congregation for the Doctrine of the Faith, Letter to the Bishops of the Catholic Church on the pastoral care of homosexual persons, no. 15, October 1, 1986)

We may not silence the increased obligation of conjugal fidelity within the family; now that legal divorce has been granted the possibility of being carried out with impunity. In the same way, we may not forget the duty of all — especially ours, the Pastors — to deplore the permissive legislation regarding abortion. […] These problems of today, to which are added others, countless and immeasurable, turn  grave, and ever more grave, of our pastoral duty, our responsibility over the People of God, and over that which is not officially of God, but is, nonetheless always ours.  (Paul VI. General Audience, May 24, 1978)

It is to be anticipated that perhaps not everyone will easily accept this particular teaching [on the illicitness of contraceptives]. There is too much clamorous outcry against the voice of the Church, and this is intensified by modern means of communication. But it comes as no surprise to the Church that She, no less than her divine Founder, is destined to be a ‘sign of contradiction’ (Lk 2:34). She does not, because of this, evade the duty imposed on her of proclaiming humbly but firmly the entire moral law, both natural and evangelical. Since the Church did not make either of these laws, she cannot be their arbiter—only their guardian and interpreter. It could never be right for Her to declare lawful what is in fact unlawful, since that, by its very nature, is always opposed to the true good of man.  (Paul VI. Encyclical Humanae Vitae, no. 18, July 25, 1968)

The Church’s Pastors have the duty to act in conformity with their apostolic mission, insisting that the right of the faithful to receive Catholic doctrine in its purity and integrity must always be respected. ‘Never forgetting that he too is a member of the People of God, the theologian must be respectful of them, and be committed to offering them a teaching which in no way does harm to the doctrine of the faith’ (cf. Cong. for the Doct. of the Faith, Instruction Donum Veritatis). (John Paul II. Encyclical Veritatis Splendor, no. 113, August 6, 1993)

Indeed, there is no lack of attempts, in public opinion and in civil legislation, to make equivalent to the family mere de facto unions or to recognize as such same-sex unions. These and other anomalies lead us with pastoral firmness to proclaim the truth about marriage and the family. Not to do so would be a serious pastoral omission that would lead people into error, especially those who have the important responsibility of making decisions for the common good of the nation. (John Paul II. Address to Bishops of Brazil on ad limina visit, no. 4, November 16, 2002)

A pastoral proposal for the family in crisis presupposes, as a preliminary requirement, doctrinal clarity, effectively taught in moral theology about sexuality and the respect for life. The opposing opinions of theologians, priests and religious that the media promote on pre-marital relations, birth control, the admission of divorced persons to the sacraments, homosexuality and artificial insemination, the use of abortion practices or euthanasia, show the degree of uncertainty and confusion that disturb and end by deadening the consciences of so many of the faithful. (John Paul II. Address to Bishops of Brazil on ad limina visit, no. 4, November 16, 2002)

But today, in many people’s consciences, the perception of its gravity [of abortion] has become progressively obscured. The acceptance of abortion in the popular mind, in behavior and even in law itself, is a telling sign of an extremely dangerous crisis of the moral sense, which is becoming more and more incapable of distinguishing between good and evil, even when the fundamental right to life is at stake. Given such a grave situation, we need now more than ever to have the courage to look the truth in the eye and to call things by their proper name, without yielding to convenient compromises or to the temptation of self-deception. In this regard the reproach of the Prophet is extremely straightforward: ‘Woe to those who call evil good and good evil, who put darkness for light and light for darkness’ (Is 5:20). (John Paul II. Encyclical Evangelium Vitae, no. 58, March 25, 1995)

The commandments of which Jesus reminds the young man are meant to safeguard the good of the person, the image of God, by protecting his goods. ‘You shall not murder; you shall not commit adultery; you shall not steal; you shall not bear false witness’ are moral rules formulated in terms of prohibitions. These negative precepts express with particular force the ever urgent need to protect human life, the communion of persons in marriage, private property, truthfulness and people’s good name. The commandments thus represent the basic condition for love of neighbor; at the same time they are the proof of that love. They are the first necessary step on the journey towards freedom, its starting-point.  (John Paul II. Encyclical Veritatis Splendor, no. 13, August 6, 1993)

If such great care must be taken to respect every life, even that of criminals and unjust aggressors, the commandment ‘You shall not kill’ has absolute value when it refers to the innocent person. And all the more so in the case of weak and defenseless human beings, who find their ultimate defence against the arrogance and caprice of others only in the absolute binding force of God’s commandment.[…] Faced with the progressive weakening in individual consciences and in society of the sense of the absolute and grave moral illicitness of the direct taking of all innocent human life, especially at its beginning and at its end, the Church’s Magisterium has spoken out with increasing frequency in defense of the sacredness and inviolability of human life. (John Paul II. Encyclical Evangelium Vitae, no. 58, March 25, 1995)

Thus the Church condemns as a grave offense against human dignity and justice all those activities of governments or other public authorities which attempt to limit in any way the freedom of couples in deciding about children. Consequently, any violence applied by such authorities in favor of contraception or, still worse, of sterilization and procured abortion, must be altogether condemned and forcefully rejected. Likewise to be denounced as gravely unjust are cases where, in international relations, economic help given for the advancement of peoples is made conditional on programs of contraception, sterilization and procured abortion. (John Paul II. Apostolic Exhortation Familiaris Consortio, no. 30, November 22, 1981)