Shared ground
Peter links these lines to what he has just said about new life and the enduring message they received (“therefore”). The passage makes two explicit moves: (1) a full break with behaviors that damage relationships—harm, deceit, hypocrisy, envy, and harmful speech—and (2) a strong desire for “pure milk” connected to “the word/message,” with the stated purpose of growth (vv. 1–2). The final line assumes prior experience: they have “tasted” that the Lord is gracious (v. 3).
The image of newborn infants emphasizes intensity and persistence of desire, not sophistication. The list in v. 1 focuses on community life: hidden manipulation (deceit), performative religion (hypocrisy), competitive resentment (envy), and speech that harms others.
Where interpretation differs
What “milk of the word/message” refers to. Some read it mainly as Scripture (heard and read in the church). Others read it mainly as the proclaimed gospel message. Many treat it as both: God’s communicated message in whatever faithful form it comes—public teaching, the remembered gospel, and the recognized writings.
Who “newborn infants” describes. Some think Peter is addressing people who are newly converted, so “milk” highlights basic instruction. Others think the infant picture is a continuing posture for all believers: even the mature keep a dependent appetite for what gives life.
How “if indeed you have tasted” functions. Some take it as straightforward confidence (“since you have tasted…”). Others hear a gentle test that exposes mere association without real experience.
What “grow” is aiming at. Some hear growth toward spiritual maturity broadly. Others emphasize growth that shows up in stable, honest community life under pressure, matching the specific relational sins named in v. 1.
Why the disagreement exists
Peter uses everyday metaphors (“milk,” “taste”) and a flexible phrase (“of the word/message”) that can point to more than one delivery form. Also, “if indeed” can be read as either assumed reality or mild challenge, and the word “grow” is not narrowed to one area in the sentence itself.
What this passage clearly contributes
This text presents growth as something God’s people receive through ongoing nourishment from God’s message, not as mere self-improvement (v. 2). It also ties receptiveness to God’s word/message to the health of a pressured community: certain speech and social behaviors are incompatible with that nourishment (v. 1). Finally, it treats Christian motivation as grounded in experienced grace—having “tasted” the Lord’s kindness makes continued desire fitting (v. 3).