Mark 9:38-41

38 John said to him, Master, we saw one driving out evil spirits in your name: and we said that he might not, because he is not one of us.

39 But Jesus said, Say not so: for there is no man who will do a great work in my name, and be able at the same time to say evil of me.

40 He who is not against us is for us.

41 Whoever gives you a cup of water, because you are Christ's, truly I say to you, he will in no way be without his reward.