38 John said to Jesus, “Teacher, we saw someone who doesn’t follow us casting out demons in your name; and we forbade him, because he doesn’t follow us.”

39 But Jesus said, “Don’t forbid him, for there is no one who will do a mighty work in my name, and be able quickly to speak evil of me. 40 For whoever is not against us is on our side."

Mark 9:38-40 - World English Bible

Us vs. them. Whoever is your enemy is my enemy. While these stark distinctions might seem childish, they do reveal the cultural mind set behind the implied question of John: how dare an exorcist who doesn't follow Jesus cast out demons in his name? Actually, this question might reflect a controversy in the early Church about faith healers and the use of his name. The name of the Lord had power, even outside the community of believers. Did they have an inherent right to its use?

Jesus answered "No" and for good reason; use of his name by others on the outside evangelized them. That insight was summed up in Mark 9:39: "... no one who will do a mighty work in my name, and be able quickly to speak evil of me."

How do you use the name of the Lord? How do you exercise its power?