1) Premise: there are no beneficial mutations; all mutations lead to decay, disease, or death.
2) From (1), some mutations cause death.
3) Presumably, some mutations cause death at a very early age, or even in utero.
4) When young children die, they go directly to heaven.
5) Going to heaven is the best possible outcome.
6) Therefore, there are beneficial mutations. QED.
(Hat tip to the skunk-dicks at Irreligiosophy.)