What's the difference between pietism and pietist?

Pietism

Definition:

• (n.) The principle or practice of the Pietists.
• (n.) Strict devotion; also, affectation of devotion.

Example Sentences:

• (1) Another influence was Pietism, a movement within Lutheranism that emphasised hard work and shunned worldly amusements.
• (2) The medicinal legalities of the Anhaltine territories developing under the influence of Enlightenment and Pietism and then characterized by philanthropism contain numerous progressive and for their age exemplary components.

Pietist

Definition:

• (n.) One of a class of religious reformers in Germany in the 17th century who sought to revive declining piety in the Protestant churches; -- often applied as a term of reproach to those who make a display of religious feeling. Also used adjectively.

Example Sentences:

• (1) Someone should point out, in these days when the constitution is so constantly and pietistically invoked, that political parties are not mentioned in the constitution, and that the prescient founders warned emphatically against them for reasons that should be clear to us now.