Thematic Bible: Who is immature

However, brethren, I could not talk to you as to spiritual [men], but as to nonspiritual [men of the flesh, in whom the carnal nature predominates], as to mere infants [in the new life] in Christ [ unable to talk yet!] I fed you with milk, not solid food, for you were not yet strong enough [to be ready for it]; but even yet you are not strong enough [to be ready for it], For you are still [unspiritual, having the nature] of the flesh [under the control of ordinary impulses]. For as long as [there are] envying and jealousy and wrangling and factions among you, are you not unspiritual and of the flesh, behaving yourselves after a human standard and like mere (unchanged) men?

Concerning this we have much to say which is hard to explain, since you have become dull in your [spiritual] hearing and sluggish [even slothful in achieving spiritual insight]. For even though by this time you ought to be teaching others, you actually need someone to teach you over again the very first principles of God's Word. You have come to need milk, not solid food. For everyone who continues to feed on milk is obviously inexperienced and unskilled in the doctrine of righteousness (of conformity to the divine will in purpose, thought, and action), for he is a mere infant [not able to talk yet]!