**817 **In fact, āin this one and only Church of God from its very beginnings there arose certain rifts, which the Apostle strongly censures as damnable. But in subsequent centuries much more serious dissensions appeared and large communities became separated from full communion with the Catholic Church - for which, often enough, men of both sides were to blame.ā The ruptures that wound the unity of Christās Body - here we must distinguish heresy, apostasy, and schism - do not occur without human sin:
Where there are sins, there are also divisions, schisms, heresies, and disputes. Where there is virtue, however, there also are harmony and unity, from which arise the one heart and one soul of all believers.
819 āFurthermore, many elements of sanctification and of truthā are found outside the visible confines of the Catholic Church: āthe written Word of God; the life of grace; faith, hope, and charity, with the other interior gifts of the Holy Spirit, as well as visible elements.ā Christās Spirit uses these Churches and ecclesial communities as means of salvation, whose power derives from the fullness of grace and truth that Christ has entrusted to the Catholic Church. All these blessings come from Christ and lead to him, and are in themselves calls to āCatholic unity.ā
820 āChrist bestowed unity on his Church from the beginning. This unity, we believe, subsists in the Catholic Church as something she can never lose, and we hope that it will continue to increase until the end of time.ā Christ always gives his Church the gift of unity, but the Church must always pray and work to maintain, reinforce, and perfect the unity that Christ wills for her. This is why Jesus himself prayed at the hour of his Passion, and does not cease praying to his Father, for the unity of his disciples: āThat they may all be one. As you, Father, are in me and I am in you, may they also be one in us, . . . so that the world may know that you have sent me.ā The desire to recover the unity of all Christians is a gift of Christ and a call of the Holy Spirit.