Even if you believe the Bible, there is nothing that "proves" or provides evidence that it is the Word of God. If you are looking for proof, you will not find it. That is like searching for dinosaurs in a beehive.
What we have in the Bible is testimony from those who have either experienced or believed in God. They wrote out a way of life, that can either be followed or discarded. All that is gold does not glitter, and the Bible (for some) contains golden threads that guide us in our choices, decisions and paths through life.
The version of "God kills babies and floods a planet" offers no insights or instructions to anyone. It is useless, it is worthless. It is like a gold miner returning to town with a wheelbarrow of dirt, leaving the gold behind.