If invited to hold forth at the podium, seeking their rapt attention, doing it in torn jeans, particularly if it "under-dresses" the congregation, is a sign of disrespect. Call me old fashioned. Maybe it is in the gay in me, but sartorial presentation matters.
This.
I have no problem if people, including the pastor, wear jeans to church. Non-baggy, non-athletic shorts won't turn me off as long as you aren't on stage. But when it comes to torn jeans, evidently stained clothing, or clear evidence that you don't care about basic hygiene, that's where I draw the line and call it blatant disrespect for god and the conregation, especially if you're on stage.