49 Now John answered and said, “Master, we saw someone casting out demons in Your name, and we forbade him because he does not follow with us.” 50 But Jesus said to him, “Do not forbid him, for he who is not against us is on our side.” (Lk. 9:49,50)
“He who is not with Me is against Me, and he who does not gather with Me scatters.” (Lk. 11:23)
Shortly after the familiar apostolic debate – ‘which one of us is the greatest?’ (Lk. 9:46) – and shortly after Jesus perceived the thoughts of His disciples and gave them an illustration, along with some instruction, about true greatness (vs.47-48), John, for whatever reason, called Jesus’ attention to something he and the others had seen at some earlier time; namely, a man who wasn’t among them but was casting out demons in Jesus’ name (vs.49). A quick glance at the verse reminds us that this guy was being used in this way. This was not a case like in the book of Acts where the seven sons of Sceva tried to cast out a demon in the name of “Jesus whom Paul preaches” and it didn’t work (Acts 19:13b). Here, the guy was actually casting out demons in Jesus’ name. So all we know about this man, which is very little, suggests that he believed in Jesus and was being used by God to advance the kingdom of God.