Pascal's Wager

Philosophical Argument
God either exists, or He does not.

If God exists, then when I die, I will go either to Hell or to Heaven.

If God does not exist, then when I die, my consciousness will simply vanish, and I will know nothing more.

If God exists, and I do not believe in Him, then I will go to Hell.

If God exists, and I do believe in Him, then I will go to Heaven.

If God does not exist, then whether or not I believe in Him, I will vanish into oblivion.

Therefore, if I do not believe in God, I will either vanish or go to Hell.

If I do believe in God, I will either vanish or go to Heaven.

Whichever way round it is, I stand to lose more by not believing in God than I do by believing in Him.

Therefore, I will believe in God.