Complex sentence: Jerome and Epiphanius both wrote how the Nazarene sect existed in their day, Lives of Illustrius Men Ch.3 Panarion 29.7.7 however, little is known how their sect disappeared or what happened to the Gospel of the Nazarenes.
Split into simpler sentences: Jerome and Epiphanius both wrote how the Nazarene sect existed in their day, Lives of Illustrius Men Ch.3 Panarion 29.7.7. However, little is known how their sect disappeared or what happened to the Gospel of the Nazarenes.