Stick it out in your class. If you're not having trouble in your class, that's great, but use this advice as a token for any future situations that may come up. If you are having problems, remember the reason you are there. You are there to help the children understand God better. Don't give up unless you're sure that being there won't help the children in any way.
Teaching is a skill, just like music or art.
Some people have it and some people don't. I personally couldn't create a great work of art if someone put one million dollars in front of me, but that doesn't mean that if I was dedicated to art, I wouldn't try as hard as I could and somehow be involved in it. You are there for your religion. If teaching isn't your skill, don't give up on the church. Position yourself somewhere else in the church.