God is God. His existence has been proven even in ages pass. In the midst of a nation with many gods, He proved himself as the only God existing. That was in the land of Egypt. When Pharaoh and his host wanted to stand against Him, He proved to them that He alone is the true God. He is the one and only God. There is no other God besides him.
The heavens and the earth were created by God. The One who put up this beautiful architectural work is the God who rules the universe. The whole creation wouldn't have been if there were no God. The things that we see which exist are the proof of God’s existence. You, yourself, are proof of God’s existence. So, am I.
The Bible is the book that reveals God to us. Everything that we need to know about God is clearly highlighted for us. If anyone has doubt about God’s existence, read the Bible and your understanding will be opened to know him.