Mark 9:38-41 “For he who is not against us is on our side.”
Two things stand out in John’s words here – they saw someone who was not following them, casting out demons, but this person did so in the name of Jesus (v. 38). It wasn’t the bare act of casting out demons, rather it was being done by someone who shared their beliefs about Jesus, which meant accepting Jesus entire theological perspective (v. 39). Jesus made clear, using all of the Hebrew scriptures, that he came to fulfill all that was written of him. This was a thoroughgoing confession, one which many so-called Christian organizations deny. However, this person was not physically following Jesus and his close disciples. The difference here is not one of theology, but of personalities, approaches, styles, and locations.
It is no different than the unique writing styles that we find among the biblical writers, and yet the message is the same. God employs the unique talents of all his children, for his cause and kingdom. The disciples should have been thankful that there were other messengers being raised up to reap the harvest. When word and deed are done in Jesus’ name, he works his work through the means of many. “For he who is not against us is on our side” (v. 40). It could be something as simple as offering them a cup of water in Jesus’ name, because they also believed that he was and is the Christ, and they would be rewarded (v. 41). We also must be thankful for all those who share this same belief, though they labour differently than we do.