While I have defended some exegetical conclusions which favor the charismatic movement, there are a number of places where some adherents are heretical and dangerous. The following list is not exhaustive:
Sever ties with non-Trinitarians. I am open to the fact that not all Pentecostals are Oneness Pentecostals. I also grant that many people in their communions, Oneness or Trinitarian, probably can’t articulate why they (dis)believe in the Trinity. That said, there is no way to justify communion with people who knowingly reject the Trinity. To commune with them is to share in their doctrine.
Only God can determine how he is to be worshiped. I realize asking many charismatics to commit to the Regulative Principle of Worship is a lot to ask. I think it is biblical to ask. I would also kindly ask my Reformed friends to realize that it sometimes takes a while to come to a biblical understanding of worship. Of course, God’s glory cannot be compromised, and God may indeed have to vindicate his honor, but wasn’t there a time when many of you did not hold to proper views of worship? Indeed, much of what I have just written could be applied to the PCA instead of the Assemblies of God!
As an addendum to the above, you need to regulate unbiblical or bizarre practices. This can include public worship, but it can also include private worship. Some charismatics of the more intellectual stripe quickly point out where many invididuals fall down on the floor “as though dead.” Yes, we do indeed see that happening. Further, one should hesitate to make categorical condemnations. However, I must point out a few things: the falling down, to the degree it happens in the Bible. is something the Spirit of God does independent of human means. In other words, we NEVER see people in the Bible lining up at the front of the church waiting for this guy to place his hands on them and “zap” them and they fall down. Ironically, the regulative principle in the NT actually regulates a lot of spiritual gifts and practices.
Edit: Scott Clark has linked to a noted Jamie Smith article on a Reformed Pentecostalism. While I don’t agree with all of Clark’s conclusions, I share his concerns. Smith comes very close to urging a syncretism of some Reformed practices and some (generally undefined) charismatic and postmodern practices. My Scottish Puritanism comes out with a vengeance here, and for somewhat personal reasons. I am not advocating charismania. I simply have a few exegetical conclusions which place me at odds with modern Reformed folk on one particular issue (though I am fully in line with much of the Scottish Reformation). Smith suggests that for icons in worship we should have–I don’t know what they are called. Think of those screens that can be placed on walls and change pictures and stuff), and instead of incense we can have exotic coffee! Really, it can’t get sillier.