After you die, you're stuck in a dimension between Heaven and Hell. Both doors have the letter H on it. There are two people in the dimension, one will tell the truth and the other will tell a lie. How do you get to Heaven by asking one question if you're planning on going there? LOL
You ask the question: What will the other one say. The liar will lie and point to the Hell door. The one that tells the truth will also point to the Hell door because that's what the liar will do.