So you when to hell now what.

[dyresand]

Five reasons for the universe existing:

1. It has always existed (even though we know that not to be true) 
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.

Fixed that for you  we do know the age of the universe.