What influence does pietism have on modern-day Lutheranisms? This topic is an expansion of a question on the English Stack
  Exchange.


What influence does pietism have on modern-day Lutheranisms?

Although I am aware that pietism has contributed positively to Lutheranism and other denominations of Christianity, I am going to focus narrowly on Lutheranism to keep this question in specific scope. The answer may discuss:


the change in attitudes towards religion between Lutheran Orthodoxy and Pietism
the change in attitudes towards religion between Pietism and Enlightenment Rationalism
why Pietism is generally not a derogatory term, but merely describes a different thinking pattern
how to identify a display of Pietistic behavior in a Pietistic Lutheran church, and how to distinguish it from one that focuses on Lutheran Orthodoxy or Enlightenment Rationalism
What influence does pietism have on modern-day Lutheranisms?

The answer to this relies on the meaning of "influence" as well as the definition of "pietism". If one takes a narrow view of pietism as a movement started by Philipp Jakob Spener, then his attempt to reform Lutheran practice has pretty much died out.

However if one defines pietism as the desire in the heart of a person to greater devotion, practice, and expression of faith, then there are examples of this in many Lutherans today.

The definition of influence also comes into play. The desire for piety can spontaneously emerge from the heart. It can also be triggered by reading or hearing about others. (In this way the influence of Spener may still be said to "influence" others).

Spener wrote a book called "Pia desideria" which listed things he thought would improve Lutheran practice. They read very much similar to what you might find in "house church" literature today.

The problem for pietism of all ages is that, like revival, it cannot be taught. Christians often tend to settle into a comfortable routine that the heart drawn to piety struggles against.

Expressions of individual and even group piety today are less a causative result of historical doctrines, than it is a resonance with those drawn to the deeper Christian life throughout history.