If We Regard the Anger, and Indignation, and Hatred of God Described in the Sacred Pages, We Must Remember that They are Not to Be Understood as Bearing the Character of Human Vices.
Moreover, if we read of His wrath, and consider certain descriptions of His indignation, and learn that hatred is asserted of Him, yet we are not to understand these to be asserted of Him in the sense in which they are human vices. For all these things, although they may corrupt man, cannot at all corrupt the divine power. For such passions as these will rightly be said to be in men, and will not rightly be judged to be in God. For man may be corrupted by these things, because he can be corrupted; God may not be corrupted by them, because He cannot be corrupted. These things, forsooth, have their force which they may exercise, but only where a material capable of impression precedes them, not where a substance that cannot be impressed precedes them. For that God is angry, arises from no vice in Him. But He is so for our advantage; for He is merciful even then when He threatens, because by these threats men are recalled to rectitude. For fear is necessary for those who want the motive to a virtuous life, that they who have forsaken reason may at least be moved by terror. And thus all those, either angers of God or hatreds, or whatever they are of this kind, being displayed for our medicine—as the case teaches—have arisen of wisdom, not from vice, nor do they originate from frailty; wherefore also they cannot avail for the corruption of God. For the diversity in us of the materials of which we consist, is accustomed to arouse the discord of anger which corrupts us; but this, whether of nature or of defect, cannot subsist in God, seeing that He is known to be constructed assuredly of no associations of bodily parts. For He is simple and without any corporeal commixture, being wholly of that essence, which, whatever it be—He alone knows—constitutes His being, since He is called Spirit. And thus those things which in men are faulty and corrupting, since they arise from the corruptibility of the body, and matter itself, in God cannot exert the force of corruptibility, since, as we have said, they have come, not of vice, but of reason.
Source: Treatise Concerning the Trinity (New Advent)