1 Peter 2:2 is a major point of contention in the King James Only controversy, but the real issues underlying the passage get lost amidst the standard KJVO rhetoric.
ESV (2016) — Like newborn infants, long for the pure spiritual milk, that by it you may grow up into salvation—”
NASB (1995) — like newborn babies, long for the pure milk of the word, so that by it you may grow in respect to salvation,
NIV (2011) — Like newborn babies, crave pure spiritual milk, so that by it you may grow up in your salvation,
KJV (1769) — As newborn babes, desire the sincere milk of the word, that ye may grow thereby:
The debate I will discuss here is between the respective translations “spiritual milk” and “milk of the word.” In this phrase, the debate is how to translate this Greek phrase, τὸ λογικὸν ἄδολον γάλα (to logikon adolon gala). There are no textual variants.
You might have seen the term λογικὸν there and went, “Hey, that sounds like λογος (logos), which is ‘word’ as in ‘In the beginning was the Word, and the Word was with God, and the Word was God.” But logikon isn’t quite logos, though they are related. Most literally, this could be translated “pertaining to reason.” If we wanted to commit the error of just taking the root of the word and running with it 2,000 years into the future without any serious study of linguistics, we would translate this “logical” and call it a day because they sound the same, but we can’t really do that because meanings of words change over time. Partially, we could have a word play here where Peter wants to make clear that “milk” is referring to the capital-w Word of God.
Pure Figurative Milk?
The translation “spiritual” is a bit odd on its face, as the word here also isn’t πνεῦμα (pneuma) or πνευματικός (pneumatikos). Grudem argues in favor of “spiritual” in this way:
Spiritual (logikos) though often used with the sense of ‘reasonable, rational’ can mean ‘mental, in idea only, i.e. figurative, not literal’ (cf. T.Levi 3:6 and Corpus Hermeticum 1.31, which speak of ‘spiritual’ [not literal] sacrifices or offerings). This seems to be the force of logikos in Romans 12:1, its only other New Testament occurrence – ‘your spiritual worship’. So here it seems to mean ‘long for pure figurative (not literal) milk’.40
[footnote 40]: The translation ‘the pure milk of the word’ (NASB, cf. AV) does not seem to be supported by known uses of logikos, and is apparently based on a mistaken assumption of similarity in sense to the related word logos, ‘word’.
Wayne A. Grudem, 1 Peter: An Introduction and Commentary, vol. 6 of Tyndale New Testament Commentaries. IVP/Accordance electronic ed. (Downers Grove: InterVarsity Press, 1988), 100. Emphasis added.
The context that follows Romans 12:1, however, strikes as having much to do with reason: “be transformed by the renewing of your mind” (v. 2); “not to think more highly of himself than he ought to think; but to think so as to have sound judgment.” (v. 3)
Milk of the Logos?
Peter probably opted for the term to clarify that the milk he had in view was the word of God. The “word” (logos), after all, was the means by which God begot believers. God’s “word” (rhēma) abides forever, and that very word is identified as the gospel preached to the Petrine believers (1:25). Hence, Peter used logikos to define milk here, so that the readers will understand that the milk by which they grow is nothing other than the word of God. The means by which God sanctifies believers is through the mind, through the continued proclamation of the word. Spiritual growth is not primarily mystical but rational, and rational in the sense that it is informed and sustained by God’s word.
Thomas R. Schreiner, 1, 2 Peter, Jude, vol. 37, The New American Commentary (Nashville: Broadman & Holman Publishers, 2003), 100.
With this word logikon, Peter tells us that spiritual growth is rational rather than mystical. Spiritual growth is not by osmosis, as in “I’m going to read my Bible each morning and see how it makes me feel” or “I’m going to read my Bible in the morning and then just get on with my day without bothering to meditate on it, make an effort to understand what it means and apply it to my life.” Or perhaps you’ve heard someone say, “I’m not to expend any effort to dig into the text for find its meaning. I’m simply going to read it, pray, and have the Holy Spirit just tell me what it means.” We need to understand with our minds what the Bible is teaching rather than just having it make us feel good. So don’t miss the aspect of rationality here. It’s not “rational” in the sense of how atheists like to hijack that term, but it’s understanding the Word with our minds. Both common English translations severely risk skipping over this understanding.
A third option exists, namely that Peter isn’t actually referring to Scripture in the first place but rather to other forms by which God sustains believers. Such other interpretations require a separately prepared response.
To that end, perhaps “pure logical milk” isn’t that bad of an understanding, so long as we’re doing our biblical linguistics in a logikos manner.