Westminster Shorter Catechism
Question 4. What is God?
Answer 4. God is a Spirit, infinite, eternal, and unchangeable, in his being, wisdom, power, holiness, justice, goodness, and truth.
Exodus 3:1-6, 13-15
Now Moses was keeping the flock of his father-in-law, Jethro, the priest of Midian, and he led his flock to the west side of the wilderness and came to Horeb, the mountain of God. 2 And the angel of the Lord appeared to him in a flame of fire out of the midst of a bush. He looked, and behold, the bush was burning, yet it was not consumed. 3 And Moses said, “I will turn aside to see this great sight, why the bush is not burned.” 4 When the Lord saw that he turned aside to see, God called to him out of the bush, “Moses, Moses!” And he said, “Here I am.” 5 Then he said, “Do not come near; take your sandals off your feet, for the place on which you are standing is holy ground.” 6 And he said, “I am the God of your father, the God of Abraham, the God of Isaac, and the God of Jacob.” And Moses hid his face, for he was afraid to look at God.
13 Then Moses said to God, “If I come to the people of Israel and say to them, ‘The God of your fathers has sent me to you,’ and they ask me, ‘What is his name?’ what shall I say to them?” 14 God said to Moses, “I am who I am.” And he said, “Say this to the people of Israel: ‘I am has sent me to you.’” 15 God also said to Moses, “Say this to the people of Israel: ‘The Lord, the God of your fathers, the God of Abraham, the God of Isaac, and the God of Jacob, has sent me to you.’ This is my name forever, and thus I am to be remembered throughout all generations.