Complex sentence: A successor for Preuss was not selected at this time (this happened later in 1880); going by a prophecy, the remaining Hamburg congregation gave themselves under the care of Apostle Menkhoff.
Split into simpler sentences: A successor for Preuss was not selected at this time (this happened later in 1880). Going by a prophecy, the remaining Hamburg congregation gave themselves under the care of Apostle Menkhoff.