The Jewish Exorcist Who Acted In His Name (9:38-41).
Talk about greatness and of those who do things ‘in the name of Jesus' seems to have stirred John's mind to consider something that had happened in the past that may well have been on his conscience, and he took this opportunity to seek to justify himself. Possibly he thought he would be commended for his action. But he had done exactly the opposite of what Jesus was talking about.
Analysis.
a John said to Him, “Teacher, we saw one casting out devils in Your name, and we forbade him because he did not follow us” (Mark 9:38).
b But Jesus said, “Do not forbid him. For there is no man who will do a work of power in My name and be able quickly to speak evil of Me” (Mark 9:38-40).
c “For he who is not against us is for us” (Mark 9:40).
b “For whoever will give you a cup of water to drink ‘because you are Messiah's' (Mark 9:41 a).
a “Truly I tell you he will assuredly not lose his reward” (Mark 9:41).
Note that in ‘a' John had forbidden doing good in His name, while in the parallel such a person would gain a reward from God. In ‘b' they must not forbid those who genuinely act in His Name, and in the parallel he refers to one who does do a genuine act in His Name. Central in ‘c' is the fact that he who is not against us is for us.
Once again the idea is of those who act in Jesus' Name. In these cases it was someone who was seeking to relieve the needs of others with no concern for greatness or recognition. Their heart s were right towards Jesus and towards God, and they should therefore be encouraged.