Charles Ellicott Commentary Matthew 18:3

"and said, Verily I say unto you, Except ye turn, and become as little children, ye shall in no wise enter into the kingdom of heaven." — Matthew 18:3 (ASV)

Unless you are converted—The English word expresses the force of the Greek, but the “conversion” spoken of was not used in the definite, half-technical sense of later religious experiences. What was needed was that they should “turn” from their self-seeking ambition and, in this respect, regain the relative blamelessness of children.

You shall not enter into the kingdom of heaven—The force of the words as spoken to the Twelve can hardly be exaggerated. They were disputing about precedence in the kingdom, and in that very dispute they were showing that they were not truly in it. It was essentially spiritual, and its first condition was the abnegation of self. Even the chief of the Apostles was self-excluded when he gloried in his primacy. The words at least help us to understand the more mysterious language of the “new birth” of water and the Spirit (John 3:3, 5), a teaching that at least one of the disputants must, in all likelihood, have heard.