Lately I've been studying and reading several books on revivals since the Reformation. A few things stand out:
1) Revival comes from the outpouring of the Holy Spirit, it cannot be generated by man.
2) Often with revival comes division from those who follow a previous or different theological path.
3) After a period of time, the revival fervor fades and often theological accuracy fades with it.
4) Most important, we need to trust Providence in all periods of history even when we no longer see the great outpouring of the Holy Spirit. God is always working even in history's darkest moments.
I can't recommend Iain Murray's Revival and Revivalism enough. Ever wonder about the altar call? Where did that come from? The oddball understanding of grace and why man has such control over his spiritual life? How he can make a decision? As good as this book is its heartbreaking as well to read the shift that took place from 1800 to 1831 that brought about the change in American thinking on these issues. I highly recommend it as we shall all understand our theological past.