From:
http://www.christian-oneness.org/essays/macarthur.html
(Ian's Letter to John MacArthur)
On the other hand, I disagree with your reading of I Corinthians 13:8. It is true, as you say, that, at some future time (future, at any rate, when the verse was written), tongues will "cease," that the verb used, pauo, implies finality and, unlike the other verbs in the last half of the verse, is in indicative mood, implying that it will cease of its own volition. However, the verb used to describe what will happen to knowledge and prophecy, katargeo, implies no less finality - it can properly be translated "to render powerless, to make empty, to annul, to abrogate, to cancel, to annihilate", being a variant of the verb argeo ("done away") used in verse 10, strengthened by compounding with the preposition kata (Wigram's Analytical Lexicon of the Greek New Testament, pp. 50, 219) — and, being in the passive mood, implies that knowledge and prophecy will be finally done away with by a force outside themselves.
The fact that the apostle includes the cessation of tongues and the doing away of knowledge and prophecy on the same list implies that they will all be halted because of the same event. But predicting the time of that event is not the point of the larger passage (vv.8-13) — the point of the passage is that, when the gifts go, love will remain. Yet the indication from the passage is that knowledge and prophecy, at the very least, which are "in part" will remain until that which is "the perfect" comes. When "the perfect" comes, we will see face to face and know fully, even as we are fully known. I Cor. 13:12.
At that time, of course, gifts like knowledge, prophecy and tongues will no longer serve any purpose, because each of us will have full knowledge in Christ. But when that happens, we will have "reached unity in the faith and in the knowledge of the Son of God, and become mature, attaining to the whole measure of the fullness of Christ," at which time evangelists, pastors and teachers will also no longer be necessary. Ephesians 4:11-13. Personally, I don't think the church has arrived at perfection yet, or that any of us knows God as well as He knows us.