I was reading today in the Sacra Pagina commentary on the Gospel of Mark. And, I was struck by the explanation given on the episode in the gospel reading for today:
The episode of the “strange exorcist” in 9:38-41 is remarkable for the attitude of tolerance it counsels toward those who are outside the circle of Jesus: “whoever is not against us is for us” (9:40). It is ironic that this advice appears shortly after the account of the disciples’ failure to cast out a demon in 9:14-29. Read in the context of a gospel written for a small Christian community facing persecution, this instruction would have encouraged a positive attitude toward the adherents of other religions while reinforcing belief in the absolute centrality of the “name of Christ” in the economy of salvation. It would also serve as a critique of Christian exclusiveness.
And this critique of Christian exclusiveness is no less valid today than in Jesus’ day.