SPN || A Deal with God || Sam/Dean || Wincest

The story is after S03E16 , Dean was killed and Sam want to make a deal to bring him back. But nobody want to make a deal with him ,eventually Sam find God and God makes a promise to let him came back to change one thought if he never really born this whole nightmare would never be true. Mary,John,Dean even Jessica would still be alive, so he came to the period when he was a fetus and killed himself. This whole idea came from the movie The Butterfly Effect(2004).