Unitarian Arianism produced unitarian Islam. According to Dr. Luther,1 who before becoming a Protestant had previously been an Augustinian monk, the A.D. 400f "Augustine held that [the A.D. 320f] Arius's punishment in hell becomes greater every day, as long as this error lasts. For Mohammed came out of this sect."
Arius , who died in A.D. 336, was a unitarian heretic who rejected the Trinity. Later, also the heretic Mohammed rejected Christianity for his own kind of Unitarianism — around A.D. 610. Indeed, shortly thereafter — he increasingly began to suppress and finally to persecute Trinitarians who resisted Islam.