You're going about this the wrong way.
The Bible gives the record of a people who would have been indistinguishable from the Edomites, the Moabites, the Hagrites and a whole list of other Middle Eastern people groups that have vanished into the past except for one thing. They experienced a history with a god Who was not like the gods of all the other nations, no matter how hard they tried to treat Him as if He were. Their only claim to be a nation at all was that He made them one. Their only claim to the land they dwelled on was that He gave it to them. Their only claim to have ever been a free people was that He freed them from their enemies. The Bible also records that during the years that this chosen nation was powerful and wealthy, the people (including the kings) worshipped other gods and worshipped their god like they did the others. It says that He sent messengers to tell them to repent and to warn them that He would send a foreign army to enslave them if they did not. Even though these prophets were despised by kings, priests and commoners, their writings have been preserved. Why? Well, when the nation was finally conquered, the survivors did consider that their prophets' warnings had been genuinely sent from their god, so they preserved them as sacred oracles. Moreover, the people preserved their identity as a nation even as captives in a foreign land. Why? Well, the same prophets who had warned of their destruction promised that their god would preserve them and bring them back, because He was not done with them. In fact, these same prophecies included the promise of a future Anointed One who would exalt them above all the other nations of the world. Even more remarkably, a motley group of fishermen and other peasants started proclaiming all over the Roman empire starting around 35 C. E. that this Anointed One had in fact come, had been killed, and had risen into an entirely new kind of life to institute His kingdom among all those who "received" Him, to use the Gospel of John's language.
The question whether the Bible is from God is one you can ponder later. First, you should give due weight to the fact that the history of the Jewish people is not like the history of any other nation in the world. The Passover is not like any other religious feast in the world (except the eucharist, which claims to be nothing other than its fulfillment). If you decide that the Bible's account of a people's history with God is not genuine, then you must decide what the real history is. Do not accept the claims of atheists who group it with other religious texts without reading those texts for yourself. I have. I've read the Epic of Gilgamesh. I've read the Egyptian Book of the Dead. I've read the Iliad, the Odyssey and the Theogony. I've read the Tale of Sinuhe. I've even taken a gander at the Gathas and Avestas. Care enough about the subject to do your own reading. Once you have done so, make your best decision, and stand by it.