When I was a young believer, I learned about about Philip Jacob Spener and the "pietistic" movement he started. At the core of it, more or less, is the assumption that faith isn't real if it's not expressed in daily devotion, acts of personal holiness, and the like. In its historical context, it confronted a church where even gross violations of moral law were common, especially among the clergy and aristocracy--in many regards much like today.
More recently, I've learned that "pietism" has become something of a dirty word to many, but also that the definition appears to have changed somewhat. The pietistic insistence on personal piety and evidence of one's salvation (by their fruit shall you know them) is transformed into works salvation.
Not fair, IMO, as Spener and his colleagues by and large remained in fellowship with orthodox churches. Yes, some of his followers, such as the "Holy Rollers," did give cause to believe they believed this, but a man can hardly be blamed for what happens with sinful men centuries after his death, can he?
Never mind that we again today find ourselves in situations where pastors and the elites (not to mention ordinary folk) are increasingly plagued by modernized versions of the same besetting sins Spener fought.
Perhaps, instead of fighting pietism, we ought to endorse a bit of it.