A very fine piece on this topic by Daniel at Doulogos got me started on this topic. As icing on the cake, he also has a great graphic to compliment the post.
The issue of tongues and healing is not really all that hard. You separate the wheat from the chaff by “knowing them by their fruits.” We have been told in several places in the New Testament that counterfeits would abound. Beloved, do not believe every spirit, but test the spirits to see whether they are from God, for many false prophets have gone out into the world. (1 John 4:1) I was looking at 1 Timothy 2 a bit ago, and it struck me, if all of us would make full use of the ordinary means of grace, we would be so equipped for service, and so busy, we wouldn’t have time to learn “tie my bowtie, tie my bowtie, tie my bowtie . . .ldiut hhvnv asldyt0 q9wnvn ,jghy pe9nn”
I guess the tongues and healing issues seem so obvious (to me) that I don’t worry much about them. I can conceive of situations, and have heard stories of missionaries, where those “gifts” advanced the gospel of saving grace, that it is genuine. I can see in those contexts where they build up the body, by saving lost souls into it. After all, what was the purpose of these gifts in the first-century church?
What worries me most is the whole issue of prophecy. Take, for instance, 1 Timothy 1:18, where Paul states that someone made some kind of a prophecy concerning Timothy and his calling as a pastor. All we hear about today is prophecies of impending disaster, or the return of our Lord (He even told us no man knows the day or the hour.), or “God told me to tell you to give me some money.” Now if someone were to say “God told me that you should become a missionary to Afghanistan.” How do you know, or how can you verify that God is really speaking to that individual. I understand the passage above in 1 John about testing the spirits; you have that Berean spirit and index everything with the Scriptures, but still, in this area, not every situation is so easy to discern.
Certainly we cannot put God in a box, and say He cannot do this or that. What we can do, under most instances, is tell when some huckster is trying to put God in a jack-in-the-box. All you have to do is look and see who is turning the crank.