Every New Testament epistle is its own unique blend of inspired reproof, rebuke, and exhortation. These three essential ingredients of preaching (2 Timothy 4:1-2) are purposefully woven into every book which is precisely tailored for its first century recipient(s). In some epistles (like Galatians), there are major doses of reproof and rebuke. In others (like Philippians), exhortation is the greatest need of its original reader(s).
In Hebrews 5:12-6:11, each of these vital spiritual nutrients is divinely stirred into the text. There is:
Rebuke—“For though by this time you ought to be teachers, you need someone to teach you again the first principles of the oracles of God; and you have come to need milk and not solid food. For everyone who partakes only of milk is unskilled in the word of righteousness, for he is a babe. But solid food belongs to those who are of full age, that is, those who by reason of use have their senses exercised to discern both good and evil” (5:12-14).
Reproof—“For it is impossible for those who were once enlightened, and have tasted the heavenly gift, and have become partakers of the Holy Spirit, and have tasted the good word of God and the powers of the age to come, if they fall away, to renew them again to repentance, since they crucify again for themselves the Son of God and put Him to an open shame. For the earth which drinks in the rain that often comes upon it, and bears herbs useful for those by whom it is cultivated, receives blessing from God; but if it bears thorns and briers, it is rejected and near to being cursed, whose end is to be burned” (6:4-8).
Exhortation—“Therefore, leaving the discussion of the elementary principles of Christ, let us go on to perfection, not laying again the foundation of repentance from dead works and of faith toward God, of the doctrine of baptisms, of laying on of hands, of resurrection of the dead, and of eternal judgment…But, beloved, we are confident of better things concerning you, yes, things that accompany salvation, though we speak in this manner. For God is not unjust to forget your work and labor of love which you have shown toward His name, in that you have ministered to the saints, and do minister. And we desire that each one of you show the same diligence to the full assurance of hope until the end, that you do not become sluggish, but imitate those who through faith and patience inherit the promises” (6:1-2, 9-12).
There is no divinely predetermined recipe for how much reprove, rebuke, and exhortation ought to be included in every sermon or inspired epistle. The people and situation at hand vary; therefore, the proper combination of reproof, rebuke, and exhortation changes as well.