Magisterium, Second Vatican Council

5. The attainment of union is the concern of the whole Church, faithful and shepherds alike. This concern extends to everyone, according to his talent, whether it be exercised in his daily Christian life or in his theological and historical research. This concern itself reveals already to some extent the bond of brotherhood between all Christians and it helps toward that full and perfect unity which God in His kindness wills.

6. Every renewal of the Church[27] is essentially grounded in an increase of fidelity to her own calling. Undoubtedly this is the basis of the movement toward unity.

Christ summons the Church to continual reformation as she sojourns here on earth. The Church is always in need of this, in so far as she is an institution of men here on earth. Thus if, in various times and circumstances, there have been deficiencies in moral conduct or in church discipline, or even in the way that church teaching has been formulated to be carefully distinguished from the deposit of faith itself these can and should be set right at the opportune moment.

Church renewal has therefore notable ecumenical importance. Already in various spheres of the Church's life, this renewal is taking place. The Biblical and liturgical movements, the preaching of the word of God and catechetics, the apostolate of the laity, new forms of religious life and the spirituality of married life, and the Church's social teaching and activity all these should be considered as pledges and signs of the future progress of ecumenism.

7. There can be no ecumenism worthy of the name without a change of heart. For it is from renewal of the inner life of our minds,[28] from self-denial and an unstinted love that desires of unity take their rise and develop in a mature way. We should therefore pray to the Holy Spirit for the grace to be genuinely self-denying, humble, gentle in the service of others, and to have an attitude of brotherly generosity towards them. St. Paul says: "I, therefore, a prisoner for the Lord, beg you to lead a life worthy of the calling to which you have been called, with all humility and meekness, with patience, forbearing one another in love, eager to maintain the unity of the spirit in the bond of peace". [29] This exhortation is directed especially to those raised to sacred Orders precisely that the work of Christ may be continued. He came among us "not to be served but to serve".[30]

The words of St. John hold good about sins against unity: "If we say we have not sinned, we make him a liar, and his word is not in us".[31] So we humbly beg pardon of God and of our separated brethren, just as we forgive them that trespass against us.

All the faithful should remember that the more effort they make to live holier lives according to the Gospel, the better will they further Christian unity and put it into practice. For the closer their union with the Father, the Word, and the Spirit, the more deeply and easily will they be able to grow in mutual brotherly love.

8. This change of heart and holiness of life, along with public and private prayer for the unity of Christians, should be regarded as the soul of the whole ecumenical movement, and merits the name, "spiritual ecumenism."

It is a recognized custom for Catholics to have frequent recourse to that prayer for the unity of the Church which the Savior Himself on the eve of His death so fervently appealed to His Father: "That they may all be one".[32]

In certain special circumstances, such as the prescribed prayers "for unity," and during ecumenical gatherings, it is allowable, indeed desirable that Catholics should join in prayer with their separated brethren. Such prayers in common are certainly an effective means of obtaining the grace of unity, and they are a true expression of the ties which still bind Catholics to their separated brethren. "For where two or three are gathered together in my name, there am I in the midst of them".[33]

Yet worship in common (communicatio in sacris) is not to be considered as a means to be used indiscriminately for the restoration of Christian unity. There are two main principles governing the practice of such common worship: first, the bearing witness to the unity of the Church, and second, the sharing in the means of grace. Witness to the unity of the Church very generally forbids common worship to Christians, but the grace to be had from it sometimes commends this practice. The course to be adopted, with due regard to all the circumstances of time, place, and persons, is to be decided by local episcopal authority, unless otherwise provided for by the Bishops' Conference according to its statutes, or by the Holy See.

9. We must get to know the outlook of our separated brethren. To achieve this purpose, study is of necessity required, and this must be pursued with a sense of realism and good will. Catholics, who already have a proper grounding, need to acquire a more adequate understanding of the respective doctrines of our separated brethren, their history, their spiritual and liturgical life, their religious psychology and general background. Most valuable for this purpose are meetings of the two sides--especially for discussion of theological problems where each can treat with the other on an equal footing--provided that those who take part in them are truly competent and have the approval of the bishops. From such dialogue will emerge still more clearly what the situation of the Catholic Church really is. In this way too the outlook of our separated brethren will be better understood, and our own belief more aptly explained.

10. Sacred theology and other branches of knowledge, especially of an historical nature, must be taught with due regard for the ecumenical point of view, so that they may correspond more exactly with the facts.

It is most important that future shepherds and priests should have mastered a theology that has been carefully worked out in this way and not polemically, especially with regard to those aspects which concern the relations of separated brethren with the Catholic Church.

This importance is the greater because the instruction and spiritual formation of the faithful and of religious depends so largely on the formation which their priests have received.

Moreover, Catholics engaged in missionary work in the same territories as other Christians ought to know, particularly in these times, the problems and the benefits in their apostolate which derive from the ecumenical movement.

11. The way and method in which the Catholic faith is expressed should never become an obstacle to dialogue with our brethren. It is, of course, essential that the doctrine should be clearly presented in its entirety. Nothing is so foreign to the spirit of ecumenism as a false irenicism, in which the purity of Catholic doctrine suffers loss and its genuine and certain meaning is clouded.

At the same time, the Catholic faith must be explained more profoundly and precisely, in such a way and in such terms as our separated brethren can also really understand.

Moreover, in ecumenical dialogue, Catholic theologians standing fast by the teaching of the Church and investigating the divine mysteries with the separated brethren must proceed with love for the truth, with charity, and with humility. When comparing doctrines with one another, they should remember that in Catholic doctrine there exists a "hierarchy" of truths, since they vary in their relation to the fundamental Christian faith. Thus the way will be opened by which through fraternal rivalry all will be stirred to a deeper understanding and a clearer presentation of the unfathomable riches of Christ.[34]

12. Before the whole world let all Christians confess their faith in the triune God, one and three in the incarnate Son of God, our Redeemer and Lord. United in their efforts, and with mutual respect, let them bear witness to our common hope which does not play us false. In these days when cooperation in social matters is so widespread, all men without exception are called to work together, with much greater reason all those who believe in God, but most of all, all Christians in that they bear the name of Christ. Cooperation among Christians vividly expresses the relationship which in fact already unites them, and it sets in clearer relief the features of Christ the Servant. This cooperation, which has already begun in many countries, should be developed more and more, particularly in regions where a social and technical evolution is taking place be it in a just evaluation of the dignity of the human person, the establishment of the blessings of peace, the application of Gospel principles to social life, the advancement of the arts and sciences in a truly Christian spirit, or also in the use of various remedies to relieve the afflictions of our times such as famine and natural disasters, illiteracy and poverty, housing shortage and the unequal distribution of wealth. All believers in Christ can, through this cooperation, be led to acquire a better knowledge and appreciation of one another, and so pave the way to Christian unity.