Re: My biggest regret for being an athiest/agnostic
God doesn't need us to believe in His Existence for Him to exist.
God is unlimited, beyond our comprehension. As is the reason for Him creating us. (I'm not talking about our purpose of life here - I'm referring to the cause of our creation).
We are limited, we experience evidence of this every moment of every day.
How would God, unlimited and infinite, manifest Himself in a way that is satisfactory to a limited and finite mind? It is an irrational and contradictory expectation to expect Allah swt to 'reveal himself' in entirety.
However, we do comprehend the laws of nature as they are also limited and within our capacity of understanding - and it is here that Allah swt has given us clear signs through plainly interrupting and warping the those laws of nature (ie miracles, which every Messenger of Allah (swt) has had to 'bring').
[Ps. Science has failed to prove Darwin's theory of evolution - that's why it's still called a 'theory' :) For starters, locate and read 'Evolution Deceit' by Harun Yahya and let me know what you think of that book. Islam recognises that human beings adapt to environments, but not evolve from anything other than the human form that Adam (as) was created in.]