The settlers landed on the faraway planet of Yeonizfaox.
They proceeded to enforce their religion on the inhabitants.
“But we have always managed to survive without worshipping anyone.”
“You have to worship our god before you can become civilised.”
“But we have always lived in peace and harmony.”
More settlers arrived.
“Forget that god, ours is much better than that, our god is the one true god. Our god will save you.”
Eventually the people of Yeonizfaox were overrun and displaced by the incomers and their new way of doing things.
There was no longer peace and harmony on Yeonizfaox.
There was a new way of living, it was called war.