Haitian Creole: is latcha a good word to use in a church sermon?

You mean latcha as in dengonn?
It depends....
If you're on the pulpit, all heated up, jumping up and down, resurrected Holy Ghost blood pumping through your veins and the congregation is egging you on .... preche pastè! preche! then you might get away with it.
So it's on a case by case basis.