Wayne Grudem is a scholar, and his approach to the New Testament gift of prophecy is refreshing in that he appeals to the thinking Christian.
Grudem correlates the Old Testament prophet to the New Testament Apostle, while arguing that the New Testament gift of prophecy is not infallible, verbally inspired speech; it is simply God bringing a thought to the mind of a believer. Grudem's argument here is pretty strong, if incomplete, I think.
On the other hand, he quotes many Charismatic authors (in a positive light, mostly) who state that the flesh affects almost all prophecy. Although prophecies need not deal with predicting the future, those prophecies which do attempt to predict the future, according to the charismatic source quoted, are wrong about 80% of the time. If we (and Grudem does not do this)project the same rate of return for non-futuristic prophecy, what we end up with is perhaps 20% of all prophecies being acutally true. If 20% of verifiable prophecies are true, then we should logically project that number to non-verifiable prophecies.
Prophecy then is God (perhaps) bringing something to the mind of a believer -- about 20% of the time believers sense a prophecy. Of course, our sinful natures may corrupt even some genuine prophecies, and no prophet is infallible. His/her prophecies must each be evaluated, not necessarily by church leaders, but by individual Christians (so there is no official word as to what we should bank on, except if heresy is involved and the elders must step in). And this gift, with all this uncertainty and potential falliblity attached, is supposed to edify the church.
Incredible as this seems, Grudem does make a good argument for the above (although he does not correlate the 80% of future-oriented prophcies with non-future). Some of his points seem valid, espeically his distinction between the Old Testament gift and the New, between God bringing something to mind in a general way (while the prophet uses his own words to express what he senses) and inspired speech.
Perhaps a better position would be that some of the early church prophets were somewhat closer in authority to Old Testament prophets, and did, in fact, prophesy with "Thus says the Lord," but that others (the majority) were given a thought regarding what God was doing or wanted done (God bringing something to mind, an experience many Christians with various stances on spiritual gifts have sensed). Perhaps that first initial aspect of the gift is no longer with us (and thus no new infallible revelation), while the second form (God bringing something to mind)is. Of course this seems to be the case with the Apostles (specially empowered founders of the church) in contrast to modern missionaries (apostes in the sense of sent ones) who are sent to regions beyond but do not bear the authority of the founding apostles.
Whether Grudem's conclusions are correct in totality, in partiality (my view), or not at all, this is the type of work we need to read for intelligent study of these difficult and divisive issues. A nice break from mindless assertions or studies with pre-existing agendas. We need to be open to the Scriptures, but must avoid playing spiritual "pretend" games.
I recommend this work to parties on all sides of the issue.