Suppose you're resigned to an agnostic position: it is impossible to tip the scale in favor of theism or atheism by reason alone. Can theism still be the preferred position? Consider the following argument.
1. If there is no God, everyone has the same fate of eternal death. (Premise)
2. The fate of eternal death is depressing. (Premise)
3. Hence, if there is no God, then everyone has a compelling reason to be depressed. (From 1 and 2)
4. All things being equal, it is more rational to believe in something that leads to happiness than in something that leads to depression. (Premise)
5. Therefore, all things being equal, it is more rational to believe in God than not. (From 3 and 4)