Why doesn't God present himself in a way that would be believable to non believers?

[Vicki]

God is spirit and He is to be worshiped spiritually. You're trying to make God into something he's not - physical and earthly. If that's all you want and that's all you're willing to see and go after - earthly and physical things - then that's all there will be for you. We can't show or prove spiritual matters to a nonspiritual entity. Otherwise, why would you think that ancient people would describe everything in modern terms? There are other descriptions in the OT of physical things that seem pretty wild that they knew them, like the currents of the oceans. You could check out the site below.

[cowboy]

The obvious conclusion is that there is no god like that.

[Pagan]

Because the christian god is NOT real.

[Beloveddog864]

He does, and those so-called Contradictions you mentioned? If You would stdy the Bible, instead of junk you picked up from atheist web sites, you would know otherwise,

Like the Bat for a bird thing?
Is a bat a bird?
http://carm.org/bible-difficulties/genes...y/bat-bird

Check for the rest
http://carm.org/bible-difficulties/genesis-deuteronomy

As Far as what science has discovered?
Science has served humanity well. Through it we have discovered countless natural laws of the universe, and we use that knowledge to make our lives easier in every area of our existence. But to limit a theist's proofs to the confines of what the atheist demands is terribly one-sided. To a Christian, there are experiences that science and logic cannot explain. The atheist needs to recognize we have experiences that are life changing. No mere psychological set of theories can explain the changes in our lives. So please, don't mock them. Can science nail down all that exists in mind, body, and soul? No. Can it quantify the beauty of a sunset, the cooing of a baby, or the love of a man and a woman? Science and logic have served us well, but they are not the ultimate truth to all things.
Of course, that does not mean we ignore science. In fact, we use it in our proofs for God. But to limit the playing field to your set of rules is an improper way to start. It is mostly an attempt to initiate control and keep command of the conversation by setting the ground rules according to your criteria.
Though an atheist may not accept biblical evidence as support for God's existence, it does not negate the fact that the Bible is evidence. Whether or not the atheist wants to accept it is another matter.