His father was Karl Dietrich Engel (1824–1913), a violinist who in 1846 became Konzertmeister (leader) of the orchestra of the Imperial Russian Theatre.

Leopold Engel went to Germany, finally settling in Dresden where he wrote extensively on the Faust legend.

He became a follower of mysticus Jakob Lorber (1800–1864) who wrote ten volumes of "inspired" teachings.

In 1891 Engel himself heard an "inner voice" which commanded him to write an 11th volume of Lorber's work, The Great Gospel of John.

This association came to an end on 3 July 1903 with Engel's expulsion along with his friend Siegmund Miller.