Eighth-century Christians feared Christian heresies more than Islam

Evidence

Like their counterparts in seventh-century Syria, they viewed their new masters as political and military rivals, not as religious ones. Indeed, for both groups of Christians, small heretical sects seemed to pose a greater spiritual menace than Islam: the iconoclasts for John of Damascus, Monophysites for Anastasius of Sinai, Migetius for several eighth-century churchmen in Spain. — John V. Tolan, Saracens, 488

Categorization

• XREF: Parallels the pre-Constantinian pattern where intra-community heresy threatened identity more than external paganism; connects to Milgrom’s point about in-group discipline.