John Piper compares the gift of teaching to the gift of prophecy: "And yet, even though the gift of teaching is fallible and even though it lacks intrinsic, divine authority, we know it is of immense value to the church. We are all edified and built up by gifted teachers. God is in it. He does use it. It is a spiritual gift.
Now compare this to the gift of prophecy. It is prompted by the Spirit and sustained by the Spirit and based on a revelation from God. God reveals something to the mind of the prophet (in some way beyond ordinary sense perception), and since God never makes a mistake, we know that his revelation is true. It has no error in it. But the gift of prophecy does not guarantee the infallible transmission of that revelation. The prophet may perceive the revelation imperfectly, he may understand it imperfectly, and he may deliver it imperfectly. That’s why Paul says we see in a mirror dimly (1 Corinthians 13:12). The gift of prophecy results in fallible prophecy just like the gift of teaching results in fallible teaching. So I would ask, "If teaching can be good for the edification of the church, could not prophecy be good for edifying as well, just as Paul says it is (1 Corinthians 14:3, 12, 26)—even though both of them are fallible, mixed with human imperfection, and in need of testing?