"Johann Arndt (or Arnd; 27 December 1555 – 11 May 1621) was a German Lutheran theologian who wrote several influential books of devotional Christianity. Although reflective of the period of Lutheran Orthodoxy, he is seen as a forerunner of pietism, a movement within Lutheranism that gained strength in the late 17th century." - (en.wikipedia.org 26.02.2020)
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