If God exists, why doesn't he show him(her)self? Most often I hear it's a test of faith. If you believe, you pass the test. If not, you fail. But there's plenty of people who believe, so why doesn't god just show him(her)self to them? Again, the most oft quoted answer is that it's a really long test of faith...perhaps as long as one's lifespan. I suppose a few wild mushrooms might shorten the time before you experience God...unicorns...pink elephants...hobbits.
The bible (or your text here") is the basis of faith, and in it, God appeared quite frequently, administering all kinds of cruel tests of faith to some very devout people. It seems that now our particular test of faith is to endlessly have faith without confirmation, up until the day you die. And you don't get to find out who passed and who failed because that ruins the whole point. Oh, and there's also many different testing organizations and their are no standard questions between them. One question, for example, is "Did God have a son?" At some test centers, the correct answer is YES, while at others, it's NO. And in some, it's a trick question...the son is God!
But here's a very interesting take on why God doesn't show himself:
(via Atheist Media Blog)