Why is 'god' a possibility?

[genkaus]

Basically one has but two choices, theism or nihilism.

I must be a special case then. I managed to make a third choice.

Obviously the benefit of theism is the promise of a rewarding afterlife whereas nihilism offers nothing but the now.

You need to brush up on your philosophy. Nihilism offers nothing - not even now.

As nihilism is scary to most (even a lot of atheists),

It's not scary to me. Just silly.

believing in a god gives a goal or purpose to life and these persons need this crutch to maintain.

And it's so wonderful to find out that once you let go that crutch, you can stand on your own.