The Muslim confession of faith is called the Shahada, and states, “There is no God but Allah and Muhammad is the prophet of Allah” (1). Foundational to the Islamic faith is monotheism, and it is considered shirk (blasphemy) to claim there is more than one God (2). Christians also believe that there is only one true God: “Hear, O Israel, the Lord our God, the Lord is one” (Deuteronomy 6:4).
However, one of the main tenants of the Christian faith is the doctrine of the Trinity, that the one God exists eternally in three distinct persons, the Father, the Son and the Holy Spirit. Muslims consider worship of the Trinity to be polytheism. The Qur’an condemns the doctrine of the Trinity, calling it blasphemy (Sura 5:17, 73-75)(3). But one major factual error pops up in the Qur’an when this passage is looked up. It claims that the Trinity is God, Jesus and Mary. Any Christian would also call this blasphemy. Still, the Qur’an also rejects Jesus’ divinity. Muslims also refer to the angel Gabriel as the Holy Spirit (4).
(1) Walter Martin, The Kingdom of the Cults (Minneapolis: Bethany House, 1997), 623.
(2) Martin, 620.
(4) M Nader, The Holy Spirit in the Quran [online]. [cite April 26, 2007.] http://www.submission.org/jesus/holy_spirit.html .
Also of Interest: Did Jesus Foretell Muhammad?