Mark 9:40

John said to him, "Teacher, we saw someone who doesn't follow us casting out demons in your name; and we forbade him, because he doesn't follow us.

But Jesus said, "Don't forbid him, for there is no one who will do a mighty work in my name, and be able quickly to speak evil of me.

For whoever will give you a cup of water to drink in my name, because you are Christ's, most certainly I tell you, he will in no way lose his reward.

Whoever will cause one of these little ones who believe in me to stumble, it would be better for him if he was thrown into the sea with a millstone hung around his neck.