Yu Yevon & Sin: Final Fantasy X a satire of God

Yevon lives within Sin.
Yevon defines Sin.
There will be a rebirth of Sin with an extermination of Sin, given the presence of Yevon.
To truly exterminate Sin, there can be no Yevon.

After defying Yu Yevon, there will be New Yevon;
After defying God, there will be a new God.
This is human nature.