Name

38. With what name does God reveal Himself?
203-209
230-231
God revealed himself to Moses as the living God, “the God of Abraham, the God of Isaac, the God of Jacob” (Exodus 3:6). God also revealed to Moses his mysterious name “I Am Who I Am (YHWH)”. Already in Old Testament times this ineffable name of God was replaced by the divine title Lord. Thus in the New Testament, Jesus who was called Lord is seen as true God.
39. Is God the only One who “is”?
2112-213 
Since creatures have received everything they are and have from God, only God in himself is the fullness of being and of every perfection. God is “He who is” without origin and without end. Jesus also reveals that he bears the divine name “I Am” (John 8:28).
40. Why is the revelation of God's name important?
206-213
In revealing his name, God makes known the riches contained in the ineffable mystery of his being. He alone is from everlasting to everlasting. He is the One who transcends the world and history. It is he who made heaven and earth. He is the faithful God, always close to his people, in order to save them. He is the highest holiness, “rich in mercy” (Ephesians 2:4), always ready to forgive. He is the One who is spiritual, transcendent, omnipotent, eternal, personal, and perfect. He is truth and love.

“God is the infinitely perfect being who is the most Holy Trinity.” (Saint Turibius of Montenegro)