The idea of God is beyond the realm of the human imagination. Sure, men imagine God to be who they deem him to be, but this god ends up looking, feeling, and thinking more like the imaginer. This is the dangerous and rotting fruit of spirituality - the notion that man controls the narrative of who God is, why He exists and His focus being supremely on them. The Bible tells a quite different story.
Genesis opens, not with an explanation of God and His existence, but with the reality that He simply is! What is critical about the way Genesis begins is not simply that it assumes God's existence but the perfection, completion, and the self-satisfying joy of God in Himself. This thinking flies in the face of the secular notions of Christianity that seek to force a theology that is from below, rather than from above. That is, notions about God that are man-centered and focused, rather than God centered. Man desperately wants God's purposes to be about their joy, happiness and blessing but God is, in our day, what He has always been in eternity: focused on Himself. He can be because there is none above or like Him.
While this may seem to make man insignificant, the opposite is the case. This teaching of God's joy being in Himself is the blueprint of what and where true and lasting joy is found. Man is satisfied and joyful based on our proximity to the one who is infinite joy. Thus, we are told that God existed without explanation so that we can know that there was a time before time began when God was simply enthralled with Himself. This reality teaches us that joy is not to be understood by the dictates of time or circumstances but by and in the Lord who exuded it before time.
Psalm 16:11 says "You make known to me the path of life; in your presence there is fullness of joy; at your right hand are pleasures forevermore." We see that proximity ("in your presence" and "at your right hand") brings the satisfaction of full joy and eternal pleasure. It is God's presence, not our circumstances, that assures and brings about the reality of satisfaction even in the dark and void of our lives. Jesus put it this way in John 15:11, "These things I have spoken to you, that my joy may be in you, and that your joy may be full." Jesus teaches us that our full joy, in this life, is His joy in us. In the context of speaking about His leaving them, Jesus assures the disciples that, in the darkness of this world, he will send the Comforter to abide in us (proximity) so that we will have His joy inside of us.
Notice, also, that Jesus begins this verse with these words: "These things I have spoken to you." Jesus is teaching us that the joy He provides is intimately connected to the Word He gives. God, in genesis 1, is not explained but described. He is described as a speaking God. Throughout Genesis 1 the phrase "And God said...." This tells us that one of the primary ways we are to see God is as One who speaks. he does not speak arbitrarily, but into the darkness. Joy comes from the speaking God and, thus, Jesus says that the joy in us that is full is connected to the things (word) He has spoken to us. We see then, in Genesis 1 that our joy is rooted in, not simply, the God who is, but the God who graciously condescends to speak life into darkness.
This is a major reason why the Lord is worthy of praise: He alone was glorified in Himself but graciously chose to involve us in His praise! Therefore, everything that was created by Him was created for that singular purpose. So, just as creation is the Lord's demonstration or proof of His existence, we are Christians are to be focused on the same. We are not to be tied down in the endless and, sometimes, fruitless debates about God's existence (though such can be accurately argued) rather, we are to do as God did in Genesis 1: demonstrate or prove His existence by acting as those created by Him and for His glory.
Genesis 1 is restated in John 15:7-8,
If you abide in me, and my words abide in you, ask whatever you wish, and it will be done for
you. 8 By this my Father is glorified, that you bear much fruit and so prove to be my disciples.
The fruit Jesus is speaking of our lives that reflect the recreative power of salvation. When we are on mission with God by speaking the Word of the gospel into the chaos of sin we are acting like men and women created for His glory. When we do that, Jesus says, we prove that we are the Creator's disciples.