John Calvin Commentary 1 Peter 1:14

"as children of obedience, not fashioning yourselves according to your former lusts in [the time of] your ignorance:" — 1 Peter 1:14 (ASV)

As obedient children, He first indicates that we are called by the Lord to the privilege and honor of adoption through the Gospel; and, secondly, that we are adopted for this purpose, so that He might have us as His obedient children. For though obedience does not make us children, as the gift of adoption is gratuitous, yet it distinguishes children from strangers.

Peter shows how far, indeed, this obedience extends when he forbids God’s children to conform to or to comply with the desires of this world, and when he exhorts them, on the contrary, to conform to the will of God. The sum of the whole law, and of all that God requires of us, is this: that His image should shine forth in us, so that we should not be degenerate children. But this cannot be unless we are renewed and put off the image of the old Adam.

Hence we learn what Christians ought to set as their goal throughout life: that is, to resemble God in holiness and purity. But as all the thoughts and feelings of our flesh are in opposition to God, and the whole inclination of our mind is hostility towards Him, therefore Peter begins with the renunciation of the world. And certainly, whenever the Scripture speaks of the renewal of God’s image in us, it begins here: that the old man with his lusts must be destroyed.

In your ignorance, he calls the time before they were called into the faith of Christ the time of ignorance. Thus we learn that unbelief is the source of all evils. For he does not use the word ignorance as we commonly do; for that Platonic dogma is false, that ignorance alone is the cause of sin. But yet, however much conscience may reprove the unbelievers, they still go astray like the blind in darkness, because they do not know the right way, and they are without the true light. In this sense, Paul says, You from now on do not walk as the Gentiles, in the vanity of their mind, who have the mind darkened, being alienated from the life of God, because of the ignorance that is in them (Ephesians 4:17).

Where the knowledge of God is absent, there darkness, error, vanity, and a lack of light and life prevail. These things, however, do not make it impossible for the ungodly to be conscious of doing wrong when they sin, to know that their judge is in heaven, and to feel an executioner within them. In short, as the kingdom of God is a kingdom of light, all who are alienated from Him must inevitably be blind and go astray in a labyrinth.

Meanwhile, we are reminded that we are illuminated with the knowledge of God for this purpose: so that we may no longer be carried away by roving lusts. Therefore, however much progress anyone has made in newness of life, so much progress has he made in the knowledge of God.

Here a question arises: Since he addressed the Jews, who were familiar with the law and were raised in the worship of the only true God, why did he charge them with ignorance and blindness, as if they were heathens? To this I answer that from this it becomes clear how useless all knowledge is without Christ.

When Paul exposed the empty boasting of those who wished to be wise independently of Christ, he justly said in one short sentence that they did not hold the head (Colossians 2:19). Such were the Jews. Although in other respects filled with countless corruptions, they had a veil over their eyes, so that they did not see Christ in the Law.

The doctrine in which they had been taught was indeed a true light, but they were blind in the midst of light as long as the Sun of Righteousness was hidden from them. But if Peter declares that even the literal disciples of the Law were in darkness like the heathens as long as they were ignorant of Christ, the only true wisdom of God, with how much greater care, therefore, must we strive for the knowledge of Him!