Mark 9:38-41, HCSB

38 John said to Him, “Teacher, we saw someone driving out demons in Your name, and we tried to stop him because he wasn’t following us.”

39 “Don’t stop him,” said Jesus, “because there is no one who will perform a miracle in My name who can soon afterward speak evil of Me. 

40 For whoever is not against us is for us.

41 And whoever gives you a cup of water to drink because of My name, since you belong to the Messiah — I assure you: He will never lose his reward.