The source of truth is the eternal love of God. That is, his inner life. As a Trinitarian community he deposits this love into the hearts of men. God has done so personally and irreversibly in the person of his Son, Jesus Christ. An infinite spirit, Jesus takes on a human nature to communicate fully all that his Father desires to heal in man. He passes this on through his pure deeds and words and it becomes the apostle’s work to comprehend and transmit this message to the entire world.
His deposit of love requires faith and therefore it is the Deposit of Faith, it is orally transmitted and written down, then interpreted by the teaching authority entrusted by Christ to the pope and bishops in union with him, the magisterium. It acts in every age as a servant to the Deposit of Faith to prepare the world for the final manifestation of the glory of Christ. By her obedience to Christ the words and deeds of the Church lead the world into union with God.