Where did God come from? Who created Him? Well you see when we consider the question of the origins of life and existence we’re always brought back to this point. With the idea of stuff exploding, the natural question is, where did the stuff that explode come from? The only possible answer (secular scientists must be aware of this but do not want to come right out and say it) is that matter (the stuff) is eternal. It has always existed.
The answer to life and existence necessarily has to be that either matter is eternal; or God is eternal. One way or another something or someone must be eternal in nature. And something or someone that is eternal has no beginning point. To be eternal means that one has existed forever. This is what the Bible tells us about God:
Psalm 90:2 Before the mountains were brought forth, or ever thou hadst formed the earth and the world, even from everlasting to everlasting, thou art God.
If we were to travel as far back as our limited minds could carry us into eternity past, into the depths of whatever has come before us, going and going, further and further, and once we stop, get going again, deeper and deeper into that far reaching endless eternity of existence past and all that lies beyond the limited boundaries of time this world has been anchored to. And for as far and as deep as we can travel into that unlimited region---we will find God is there. God existed. God lived.
When Moses asked what His name was, God answered:
Exodus 3:14 And God said unto Moses, I AM THAT I AM:
“I AM”---the statement that signifies life and existence. He is the great I AM, the ever existent One.
I’ve wondered exactly the same thing you’ve wondered. How is it possible for such an incredible
Being to actually exist? How could there be an eternal Being? And not just any being, but a Being that possessed all power and knowledge and goodness. An eternal perfect Being. What wonders He possesses in Himself. Yet God does indeed reveal Himself as this glorious eternal Being. Of course, since Jesus was God in the flesh it magnifies the magnificence of His humbling Himself and becoming man. By the way when questioned by the Jews Jesus made this comment:
John 8:57 Then said the Jews unto him, Thou art not yet fifty years old, and hast thou seen Abraham?
58 Jesus said unto them, Verily, verily, I say unto you, Before Abraham was, I am.
Clearly Jesus is making reference to what God said of Himself at the burning bush. He is the embodiment of this awesome everlasting God.
How is it possible for a Being to always have existed? I have no idea. The Person of God is too far above us. His ways are too high for us to grasp while in our present finite condition. But the people of God will one day enter into heaven and meet God face to face. He will dwell with us and we with Him. Can you imagine having access to Eternal God? And asking Him questions (just as people asked Christ questions)---the Bible reveals that God loves to teach. And the people of God love to learn. We will be learning much about eternity past as we dwell in His presence into eternity future.