Thus the entire office of justice in this respect becomes an agency for goodness: whatever it condemns by its judgment, whatever it chastises by its condemnation, whatever (to use your phrase) it ruthlessly pursues, it, in fact, benefits with good instead of injuring. Indeed, the fear of judgment contributes to good, not to evil. For good, now contending with an enemy, was not strong enough to recommend itself by itself alone.
…We dread the Creator’s tremendous threats, and yet scarcely turn away from evil. What, if He threatened not? Will you call this justice an evil, when it is all unfavourable to evil? Will you deny it to be a good, when it has its eye towards good? What sort of being ought you to wish God to be? Would it be right to prefer that He should be such, that sins might flourish under Him, and the devil make mock at Him? Would you suppose Him to be a good God, who should be able to make a man worse by security in sin? Who is the author of good, but He who also requires it? In like manner who is a stranger to evil, except Him who is its enemy? Who its enemy, besides Him who is its conqueror? Who else its conqueror, than He who is its punisher? Thus God is wholly good, because in all things He is on the side of good.
…How can I follow after the reward of innocence, if I have no regard to the requital of wrong-doing?
…Thus far, then, justice is the very fulness of the Deity Himself, manifesting God as both a perfect father and a perfect master: a father in His mercy, a master in His discipline; a father in the mildness of His power, a master in its severity; a father who must be loved with dutiful affection, a master who must needs be feared; be loved, because He prefers mercy to sacrifice; be feared because He dislikes sin; be loved, because He prefers the sinner’s repentance to his death; be feared, because He dislikes the sinners who do not repent.
Accordingly, the divine law enjoins duties in respect of both these attributes: Thou shalt love God, and, Thou shalt fear God. It proposed one for the obedient man, the other for the transgressor.
Tertullian
The Five Books Against Marcion, Book II
Chapter XIII