The Heresy 101 of St. John of Damascus: Doctrinal Differences between Christianity and Islam in Comparative Perspective

Klara Toneva, The Heresy 101 of St. John of Damascus: Doctrinal Differences between Christianity and Islam in Comparative Perspective. The earliest Christian perspective on Islam is that of St. John of Damascus, whose argument is fundamentally theologically oriented. This research focuses on Heresy 101: Ishmaelites, analyzing the doctrinal differences between Christianity and Islam in a critical and comparative manner. Adhering to the Jewish understanding of the absolute transcendence of God, the Qur’an presents its own approach to the ideological clash with Christianity. It rejects the essence of Christian doctrine, specifically the Incarnation of the Word of God, and the salvation resulting from this Incarnation. Islam does not accept the divine dignity of the Holy Spirit; thus, the mention of the Spirit of God in the Qur’an refers to the spirit that belongs to Allah. To counter the anti-Christian Islamic perspective, St. John adduces arguments against the Qur’anic rationalization of Trinitarian doctrine. These arguments present the Holy Trinity as a state of relations with the One and Only God, emphasizing the monarchy within the Holy Trinity and the power of the Cross of Christ. The main purpose of this paper is to demonstrate that Islam fails to transcend Old Testament notions and remains disconnected from the freedom, love, and grace articulated in the New Testament. The relationship between God and humankind in Christ through the Holy Spirit remains unacceptable to Islamm.