Imitation of Christ
The popularity of prayer in the period of the Middle Ages has been connected to the "Devotio Moderna" and related devotion, where meditation on and identification with the sufferings of Christ was encouraged by writers such as Thomas à Kempis author of "The Imitation of Christ" or mostly encouraged by the Groote to focus on the personal structure of simplicity, obedience, and followed the book The Imitation of Christ circulating from the 1420s.