After having taught the faithful that they had been regenerated by the word of God, he now exhorts them to lead a life corresponding with their birth. For if we live in the Spirit, we ought also to walk in the Spirit, as Paul says. (Galatians 5:25.) It is not, then, sufficient for us to have been once called by the Lord, except we live as new creatures. This is the meaning. But as to the words, the Apostle continues the same metaphor. For as we have been born again, he requires from us a life like that of infants; by which he intimates that we are to put off the old man and his works. Hence this verse agrees with what Christ says,
“Except ye become like this little child, ye shall not enter into the kingdom of God.” (Matthew 18:3.)
Infancy is here set by Peter in opposition to the ancientness of the flesh, which leads to corruption; and under the word milk, he includes all the feelings of spiritual life. For there is also in part a contrast between the vices which he enumerates and the sincere milk of the word; as though he had said, “Malice and hypocrisy belong to those who are habituated to the corruptions of the world; they have imbibed these vices: what pertains to infancy is sincere simplicity, free from all guile. Men, when grown up, become imbued with envy, they learn to slander one another, they are taught the arts of mischief; in short, they become hardened in every kind of evil: infants, owing to their age, do not yet know what it is to envy, to do mischief, or the like things.” He then compares the vices, in which the oldness of the flesh indulges, to strong food; and milk is called that way of living suitable to innocent nature and simple infancy.
1. All malice There is not here a complete enumeration of all those things which we ought to lay aside; but when the Apostles speak of the old man, they lay down as examples some of those vices which mark his whole character.
“Known,” says Paul, “are the works of the flesh, which are these,” (Galatians 5:19;)
and yet he does not enumerate them all; but in those few things, as in a mirror, we may see that immense mass of filth which proceeds from our flesh. So also in other passages, where he refers to the new life, he touches only on a few things, by which we may understand the whole character.
What, then, he says amounts to this, — “Having laid aside the works of your former life, such as malice, deceit, dissimulations, envyings, and other things of this kind, devote yourselves to things of an opposite character, cultivate kindness, honesty,” etc. He, in short, urges this, that new morals ought to follow a new life.