Jesus answered - Not in the language of compliment: - he saw the state of Nicodemus's soul, and he immediately addressed himself to him on a subject the most interesting and important. But what connection is there between our Lord's reply, and the address of Nicodemus? Probably our Lord saw that the object of his visit was to inquire about the Messiah's kingdom; and in reference to this he immediately says, Except a man be born again, etc.
The repetition of amen, or verily, verily, among the Jewish writers, was considered of equal import with the most solemn oath.
Be born again - Or, from above: different to that new birth which the Jews supposed every baptized proselyte enjoyed; for they held that the Gentile, who became a proselyte, was like a child new born. This birth was of water from below: the birth for which Christ contends is ανωθεν , from above - by the agency of the Holy Spirit. Every man must have two births, one from heaven, the other from earth - one of his body, the other of his soul: without the first he cannot see nor enjoy this world, without the last he can not see nor enjoy the kingdom of God. As there is an absolute necessity that a child should be born into the world, that he may see its light, contemplate its glories, and enjoy its good, so there is an absolute necessity that the soul should be brought out of its state of darkness and sin, through the light and power of the grace of Christ, that it may be able to see, ιδειν , or, to discern, the glories and excellencies of the kingdom of Christ here, and be prepared for the enjoyment of the kingdom of glory hereafter. The Jews had some general notion of the new birth; but, like many among Christians, they put the acts of proselytism, baptism, etc., in the place of the Holy Spirit and his influence: they acknowledged that a man must be born again; but they made that new birth to consist in profession, confession, and external washing. See on John 3:10 ; (note).
The new birth which is here spoken of comprehends, not only what is termed justification or pardon, but also sanctification or holiness. Sin must be pardoned, and the impurity of the heart washed away, before any soul can possibly enter into the kingdom of God. As this new birth implies the renewing of the whole soul in righteousness and true holiness, it is not a matter that may be dispensed with: heaven is a place of holiness, and nothing but what is like itself can ever enter into it.