Truth

41. In what way is God the truth?
214-217
231

God is Truth itself and as such he can neither deceive nor be deceived. He is “light, and in him there is no darkness” (1 John 1:5). The eternal Son of God, the incarnation of wisdom, was sent into the world “to bear witness to the Truth” (John 18:37).

Perfect

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)

Is

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).

YHWH

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.

God is one

37. Why does one profess belief that there is only one God?
200-202
228

Belief in the one God is professed because he has revealed himself to the people of Israel as the only One when he said, “Hear, O Israel, the Lord our God is one Lord” (Deuteronomy 6:4) and “there is no other” (Isaiah 45:22). Jesus himself confirmed that God is “the one Lord” (Mark12:29). To confess that Jesus and the Holy Spirit are also God and Lord does not introduce any division into the one God.

Source

“I believe in God the Father Almighty, 
Creator of heaven and earth.”

36. Why does the Profession of Faith begin with the words, “I believe in God”?
198-199

The Profession of Faith begins with these words because the affirmation “I believe in God” is the most important, the source of all the other truths about man and about the world, and about the entire life of everyone who believes in God.

Apostles' Creed

35. What are the most important symbols of the faith?
193-195 

They are the Apostles' Creed which is the ancient baptismal symbol of the Church of Rome and theNicene-Constantinopolitan Creed which stems from the first two ecumenical Councils, that of Nicea (325 A.D.) and that of Constantinople (381 A.D.) and which even to this day are common to all the great Churches of the East and the West.