Lull argued Islam was incomplete rather than false, implying the Christian creed

Evidence

Lull constantly presupposed, but normally treated as superfluous to assert, the Muslim belief in one God. He was aware that historically the Prophet called the Meccans away from paganism. The sum of all the controversy that he maintained against Islam through so long a life was to assert that the Christian doctrine of the Trinity and of the Incarnation is more appropriate to belief in the unity and power of God than Islamic definitions are. The point of this argument was that Muslim belief implies, although Muslims will not accept, the Christian creed. — Norman Daniel, Islam and the West, 263

Categorization

• DEFINE: Clarifies how a medieval Christian apologist framed Islam as incomplete truth rather than false religion — a theological strategy distinct from outright refutation.
• XREF: connects to: Lull argued Muslim monotheism was incomplete, not false, and only the Trinity proved it.