Having described the Word of God as a seed which gives life and as a cleansing stream which gives love, Peter moves on to explain how that spiritual life and love can develop. First, they have to put away several ugly features that may arise in their hearts, features such as ‘all malice and all deceit and hypocrisy and envy and all slander’ (2:1). What marks each of these features is that they are expressions of hatred – they are means of destroying another person.
In contrast, believers are to be like ‘newborn infants’ who desire their mother’s milk. Peter is not suggesting that his readers become childish or simplistic in their outlook. Instead he is saying that spiritual development can only occur in a person who does not have the nasty traits mentioned in verse 1. These traits are the spiritual equivalents of diseases that would prevent a child from developing. There will not be any spiritual growth in a heart that gives space to these traits.
What does Peter have in mind by ‘pure spiritual milk’? It was common in Peter’s time, as in our own, for milk to be watered down – he uses terminology that was common among traders for such a practice. So he has in mind a product that can be spoiled by additions being made to it.
In what ways does an infant desire milk? He craves for it instinctively (he does not need any lessons on how to develop an appetite – if he does not have an appetite, he is unwell), he craves for it incessantly (he desires it repeatedly), and he craves for it impatiently (he is frustrated if something stops him having it). This is how believers are to long for God’s Word.
When they use the Word of God in this way, they develop spiritually. Peter says that such ‘will grow up into salvation’. This is a reminder that salvation, in its biblical usage, covers more than the initial forgiveness of sins and the future deliverance from sin when we die or when Jesus returns. In addition, the term covers various experiences in the Christian life – they experience the sweetness of the promises of God, they discover the restoration it can give when they are spiritually weary, the guidance it contains for their spiritual journey, the communion it enables them to have with the risen Lord, the assurance it gives concerning the future.
This overall experience is described by Peter as tasting that the Lord is good. By ‘Lord’, Peter has Jesus in mind (he is referred to in the next passage as the one to whom Peter’s readers have come). Peter uses the illustration of eating a meal that gives sustenance to depict the spiritual provision that Jesus provides (incidentally, Peter is quoting from Psalm 34, a pointer to the fact that the Lord in that psalm is Jesus). Perhaps Peter was recalling the teaching of Jesus when he said that his followers had to eat his flesh and drink his blood. In any case, he was reminding his readers of their diet. They were not to eat the same food as those among whom they were sojourning, but they were to carry on eating the same spiritual food as they had been doing since their conversion.