So you when to hell now what.

[KevinM1]

Five reasons for the universe existing:

1. It has always existed
2. It was farted out by a giant space whale
3. It's actually a complex simulation
4. It's the delusion of a single intelligence
5. It's actually the afterlife, we simply don't remember our real lives

Note, that I don't believe in 2-5, but it's trivial to simply state reasons for its existence. And 2-5 are no less fanciful than your three gods in one, with one sacrificing himself to himself because humanity sucks so bad.