For we know in part - Compare the note on 1 Corinthians 12:27. This expression means “only in part;” that is, “imperfectly.” Our knowledge here is imperfect and obscure. It may, therefore, all vanish in the eternal world amidst its superior brightness; and we should not regard that as of such vast value which is imperfect and obscure; compare the note at 1 Corinthians 8:2. This idea of the obscurity and imperfection of our knowledge, as compared with heaven, the apostle illustrates 1 Corinthians 13:11 by comparing it with the knowledge which a child has, compared with that in maturer years and 1 Corinthians 13:12 by the knowledge which we have in looking through a glass - an imperfect medium - compared with that which we have in looking closely and directly at an object without any medium.
And we prophesy in part - This does not mean that we partly “know” the truths of religion, and partly “conjecture” or “guess” at them; or that we know only a part of them, and “conjecture” the remainder. But the apostle is showing the imperfection of the prophetic gift; and he observes, that there is the same imperfection which attends knowledge. It is only in part; it is imperfect; it is indistinct, compared with the full view of truth in heaven; it is obscure, and all that is imparted by that gift will soon become dim and lost in the superior brightness and glory of the heavenly world. The “argument” is, that we ought not to seek so anxiously that which is so imperfect and obscure, and which must soon vanish away; but we should rather seek that love which is permanent, expanding, and eternal.