You are to assume the possibility that God exists. If you assume otherwise, you will be eternally doomed. Once you assume that God may exist, you are to start seeking Him all of your life until you find Him. If you fail to find Him, you will be eternally doomed – no question about it.
Indeed, He guides whom He wills, the Sacred Scriptures tell you. But if you end up concluding yourself that He does not exist after all, it is entirely your fault—even though you were simply not one of the fortunate ones whom God willed to guide—and you will be doomed eternally without a doubt and without a question.
But ... what a coincidence that I was born into the right religion! What a coincidence!
This reminds me of the quote I constantly read on certain Muslims' FB profiles that read something like:
“I’d rather live my life believing in God’s existence and die to find out that He does not exist than to live my life denying His existence only to die and learn that He does exist.”
What? This is what all it comes down to, a mere probability that He does or does not exist, a chance you take by believing in Him? This should contradict the basic belief that the Quran attempts to promote, which is (as many Muslims will tell us over and over) to reason, reason, and reason. The belief promoted by the above quote, however, suggests that it's better to be safe than sorry. So you're just gonna go with the flow today that JUST IN CASE God exists, you're on the safe side ... just in case.
That's what I understand from comments that suggest that one should believe in God in order to avoid feeling guilty. How does this work?
If you can't prove it, never talk about proof: Simply say, "It's all about faith; I have FAITH that God exists, but I can't prove it." That's what an honest person who hasn't discovered any reasons for God's existence should/would say. Why argue over it? If God exists, He exists; if God doesn't exist, God doesn't exist. Don't bother "proving" to anyone that God exists because there's absolutely NO proof, unless you have some individual experiences and visions that have proven His existence to you -- in which case, you should not expect everyone else to believe in God just because you've experienced such miraculous things. Even the greatest of scholars, intellectuals, thinkers, philosophers have failed to provide any evidence of God's existence.
However, as logic teaches us, absence of evidence is not evidence of absence. This is to say that just because the existence of God cannot be proven does NOT mean that there is indeed no evidence for God's existence and that He therefore does not exist. I find it rather silly and ignorant of people to think that just because there's no evidence that God exists, He does not exist.
As for me, my belief in God is based about 75% on faith and 25% on some individual experiences I have had that have proven to me that God exists. Those experiences, I never discuss with anyone and feel no need to. Nonetheless, I simply cannot imagine not believing in Him. This isn't to say that, hey, I believe in God so you should, too. No, not at all. On the contrary, I believe everyone should explore for themselves what/who God is (for many people, God isn't an individual deity/entity; God is, for them, a concept) and whether or not they should or need to believe in Him -- or Her.
Reminder: Think. Question. Discover. Believe.
For those interested in exploring questions of religion and philosophy, I recommend the following books (I will post more later on, promise; feel free to recommend your favorites as well).