‘But Jesus said, “Do not forbid him. For there is no man who will do a work of power in my name and be able quickly to speak evil of me. For he who is not against us is for us.” '
Jesus recognised immediately that the man's success was sufficient proof that the man's heart was right and that God was with him. Such a man clearly believed in Jesus and His words and had responded to them. He had a high view of Jesus. Thus he would not criticise Jesus or run Him down but would gladly use any opportunity that arose out of his activity to point men to Jesus. Jesus could only encourage such activity, as He had encouraged the Gadarene ex-demoniac.
As already mentioned we can contrast with this Acts 19:13-17 where men did what seems on the surface to be the same, but they were simply using Jesus' name as an exorcist's tool. They did it for their own benefit rather than to glorify God. There they were unsuccessful and discovered that Jesus' name was not to be trifled with. Such use of sacred names by exorcists occurred widely. They did not always mean that the exorcist gave much credence to the one whose name they used, and there are many examples from Egyptian papyri. The use of Jewish sacred names was quite popular. The Jews with their mysterious religion and mysterious invisible God were often seen as harbouring mysterious powers. One such papyrus contained the formula, “I adjure you by Jesus the God of the Hebrews” a most interesting combination by some who were clearly somewhat hazy about distinctions.
Compare also Matthew 7:22 which suggests that many did wrongly seek to use the name of Jesus and were even at times successful in His name, possibly because of psychological healing, without necessarily being true men of God. But Jesus was prepared to give such men the benefit of the doubt, as He did with Judas, and would not forbid them. However, He did warn them not to be complacent, and that in the end their genuineness would be judged by God. To have acted in His name is not the same as to be truly His.
‘A work of power.' The Greek is literally ‘a power'.
‘For he who is not against us is for us.' This does not mean that anyone who was not antagonistic was necessarily to be seen as a supporter and that what mattered was tolerance. Many were apathetically neutral and would not come under the description of supporter. Jesus would not describe them as ‘for Him'. What Jesus was saying was that where men were active in seeking to serve God, as this man was, they would, at times, be required to take up an attitude towards Jesus, and those who did not oppose Him or attack Him but defended His ministry thereby demonstrated that they were for Him and His work, even if they did not follow Him directly (compare Numbers 11:26-29). Jesus welcomed all who were truly for God.
Elsewhere at a different time He would say what seems the opposite, ‘He who is not with me is against me' (Matthew 12:30; Luke 11:23). But there He was indicating that to refuse to make some response to Jesus and His teaching and to remain in apathetic neutrality to Him thereby demonstrated the attitude of one who was opposing the will and call of God. On the other hand the man spoken of here in Mark was actually showing that He was ‘for' Jesus, and was being very active in being so. There was nothing neutral about him.