Some well intentioned people misuse Mark 9:38-40:

John said, "Teacher, we saw someone casting out demons in your name, and we forbad him, because he has not been following us." Jesus replied, "Do not forbid him, for no one doing a miracle in my name can quickly speak evil of me. He who is not against us is for us."

Some denominationalist and charismatic people assert that the message in Mark shows that no matter what doctrine a preacher sets forth, he is not to be criticized so long as he claims to be "for" Jesus. Those people praise diversity and pluralism in religion. They do not think that it is possible to be "against" Christ as long as they say they are "for" him.

Truly none of those sincere people means to be "against" Christ, but Jesus' preview of the judgment shows that being "for" Christ requires more than saying so:

Not everyone who says to me, "Lord, Lord," will enter into heaven's kingdom, but the one who does the will of my heavenly Father. Many will say to me in that day, "Lord, Lord, have we not prophesied in your name, and in your name have we not cast out demons, and in your name have we not done many miracles?" Then I will say to them, "I have never known you" (Matthew 7:21-23).

Thus Jesus asserted that the only right way to know if one is "for" Christ is not by saying, "Lord, Lord," but by doing "the will of" the heavenly Father (Matthew 7:21).

All that we uninspired humans can know about "the will of" the heavenly Father is in the New Testament, to which we are not to add and from which we are not to subtract (1 Corinthians 4:6, ASV; 2 John 9-11; Revelation 22:18-19).

In the New Testament, we find that Christ passed on his authority to bind and to release to his apostles (Matthew 16:19; 18:18), which makes it necessary that we all devote ourselves to "the doctrine of the apostles" (Acts 2:42). One of them wrote, "He who knows God hears us. He who is not of God does not hear us. By this we know the spirit of truth, and the spirit of error" (1 John 4:6).

Consequently, everyone is either "for" Christ or "against" him: "He who is not with me is against me" (Matthew 12:30), and "He who not against us is for us" (Mark 9:40). The result is that many today who aspire to be "for" Christ are "against" him," for they refuse to be guided by "the doctrine of the apostles":

1. He who says that he is saved without baptism is "against" Christ, for baptism "saves you" (1 Peter 3:21).

2. He who says that babies are to be baptized is "against" Christ, for baptism is only for those old enough to believe (Mark 16:16; Acts 8:37).

3. He who says that baptism may be administered by sprinkling water on a person is "against" Christ, for baptism is a burial (Romans 6:4; Colossians 2:12).

4. He who says that "one faith is as good as another" is "against" Christ, for in the apostles' doctrine is only "one faith" (Ephesians 4:5).

5. He who says that "one church is as good as another" is "against" Christ, for Jesus only built one church (Matthew 16:18).

6. He who says that "one name is as good as another" is "against" Christ, for the name "Christian" is the only name listed in the apostles' doctrine (1 Peter 4:16).

7. He who advocates women being preachers is "against" Christ, for "it is a disgrace for a woman to speak in the church" (1 Corinthians 14:15).

8. He who teaches that fornication is not the only reason for divorce and remarriage is "against" Christ, for he who divorces and marries again for any other reason "commits adultery" (Matthew 19:9).

9. He who condones homosexuality is "against" Christ, for homosexuality is "against nature" (Romans 1:26-27).

10. He who denies that a God of love could send some people into "everlasting punishment" is "against" Christ, who said that there is "the hell of fire" (Matthew 5:22; 25:46).

Thus we see that the same Lord who spoke Mark 9:38-40 also spoke Matthew 7:21. If we are "for" Christ, we must adjust ourselves to all that he said. After that lesson is learned, we are ready to turn to his words in Mark 9:38-40:

John the apostle saw a man casting out demons (devils) in the name of Jesus, a man John did not know, but apparently, John saw that the man was not a fake. He really was casting out demons in Jesus' name, but he was not one of the apostles. So, John on his own told the man to quit, and then relayed what he had done to Jesus.

Jesus showed John that one did not have to be one of the apostles to be an approved exorcist. Apparently, unknown to John, Jesus had endowed that man with miraculous power. Perhaps he was one of the seventy-two that Jesus had dispatched with miraculous power "into each city and place where he was going" (Luke 10:1). Then we read that the "seventy two returned joyfully, saying, 'Lord, even the demons are subject to us in you name'" (Luke 10:10).

Apparently then, the exorcist of Mark 9:38-40 was a true disciple of Jesus, though unknown to John, and John was wrong in thinking that all exorcists had to be apostles.

Jesus would not have complimented the exorcist of Mark 9:38-40 if he had been among those who had "rejected the counsel of God against themselves, being not baptized of John" (Luke 7:29-30). Jesus thought that the baptism of John was so important he walked some 70 miles "from Galilee to the Jordan to John to be baptized by him" (Matthew 3:13). Consequently we know that the exorcist of Mark 9:38-40 had also been baptized by John.