Thanks everyone for the help and for that link. Some things about the revival are still unclear to me and I want to do some more research.
I know that, despite it being a move of God, there definately were many excesses, as is sadly the case with most revivals.
Reading through the book some more, I think there are many good things to glean from it. However, in some cases it's extremely difficult to distinguish the soulish from the spiritual, the true from the countefeit. Penn-Lewis and Roberts take the near-impossible task of this type of discernment upon themselves, leaving much room for error. I believe it was Jonathan Edwards himself who admitted that the only true way to know if a manifestation was spiritual or demonic was to examine its fruit--a holy, transformed, persevering life that gives glory to God. It would be interesting to research the lives of many of these people in the Welsh revival to see continued to burn out for the Lord after it was over.
Another thing I didn't agree with in the book was that, as compton pointed out, the author goes too far in some areas, leaving you with discouragement, doubt, and distrust in the Lord, because for all you know in your attempt to draw near to Him you might be opening yourself up to demons!
Matthew 7:7-11 says,
[i]“Ask, and it will be given to you; seek, and you will find; knock, and it will be opened to you. 8 For everyone who asks receives, and he who seeks finds, and to him who knocks it will be opened. 9 [b]Or what man is there among you who, if his son asks for bread, will give him a stone? 10 Or if he asks for a fish, will he give him a serpent? [/b] 11 If you then, being evil, know how to give good gifts to your children, how much more will your Father who is in heaven give good things to those who ask Him! [/i]
These verses always encourage me to seek His presence and the fullness of His Spirit. God has already poured out spiritual gifts on me (that are in accordance with Scripture), and whenever I doubt and feel like they may have not been from the Lord I remember this passage.