We have every reason to believe that there is God. God has revealed himself to us in everywhere. He has shown us everything about him that we do not have reason to doubt His existence. God is not hidden from us in anyway. We know him. We have seen the works of His hands.
The Bible says that it is the fool who says that there is no God. So, the rejection of God's existence is an act of foolishness. How could you reason it well and come to the conclusion that there is no God. Who created you? Who created all the beautiful things that we have in this world. Look at all the animals and the various plants growing everywhere. Who could have created them in all their various beautiful species if there is no God?
This is my conclusion: there's God. He rules through all the earth. He is the owner of life. We only see ourselves existing but we don't know how we will die. We don't know where life goes when people die. God owns all. So, every understanding mind will accept the existence of God.