Monotheism is one of the similarities between Islam and Christianity and monotheism is also one of the major differences.
The difference is that Muslims are Unitarian monotheists and Christians are Trinitarian monotheists
The question therefore is not monotheism, but whether Trinitarian or Unitarian monotheism is true.
The Bible and Monotheism
Without doubt, the Old and New Testaments affirm monotheism (Deuteronomy 6:4; Mark 12:29), but not the Unitarian monotheism of the Quran. Unitarian monotheism is foreign to the Christian Scriptures, both Old and New Testaments.1
Other biblical examples of monotheism that are not affirmed in the Quran can be found with:
- The Angel of the LORD (Genesis 18:1-2,17; 32:28-30). These are texts wherein God appears in the form of a man.3
- Statements King David made in the Psalms (Psalm 2; 45:6-7 with Hebrews 1:8-9; 110:1 with Matthew 22:35-46)
- The Prophet Isaiah (Isaiah 48:16)
These are not full-blown Trinitarian texts, but these texts are not compatible with Unitarian monotheism. However, they are compatible with Trinitarian monotheism and what Jesus revealed.
In the gospels Jesus Christ gives the definitive answer to true monotheism.4
- Jesus has an Old Testament name meaning “Yahweh saves” (Matthew 1:21; cf. Jonah 2:9).
- Jesus also has the Name “Immanuel” meaning God with us (Matthew 1:23).
- Jesus forgave sins; something only God can do (Mark 2:1-13).
- Jesus said, “Before Abraham was, I am” thus identifying Himself with the way God revealed Himself to Moses in the burning bush (John 8:58-59 with Exodus 3:14-15).
- Jesus affirmed the unity of God when He taught, “I and the Father are one” (John 10:30).
- Jesus accepted worship from others (Matthew 8:2; 14:33; 15:25; 20:20; 28:17; Mark 5:6).
Jesus went to the cross for His claims about God
- Jesus confessed to being the Christ5 before the Jewish Sanhedrin and was condemned for blasphemy (Matthew 26:63-66).
The Jewish Sanhedrin was wrong for condemning Jesus to death for blasphemy, because Jesus testified to the truth.
- The Good News of the Gospel is that Jesus was vindicated when He rose again from the dead (1 Corinthians 15:1-4).
Jesus is the reason Christians are Trinitarian monotheists (cf. Hebrews 1:1-3).
Trinitarian Monotheism is a Reason the Quran is not the Word of God
Is the Quran the Word of God? The simple answer: No. The Quran cannot be the Word of God because the Quran denies the One True God of the Bible. The Quran does not affirm Trinitarian monotheism (cf. Quran 4:171; 5:73).6 Unitarian monotheism is foreign to both Old and New Testament revelation.
An Invitation to Believe in the One True God
If you believe in Jesus, then you should be a Trinitarian monotheist who confesses Jesus as Lord and Savior (John 20:27-28). Believe in Jesus and be baptized in the Triune Name of God (Matthew 28:18-19; Acts 2:36-42).
- Islamic monotheism is not as “absolute” or “strict” as Muslims sometimes claim.
Islam claims “absolute monotheism” and yet Allah speaks about himself in the plural more than seventy times in the Quran. How is this absolute? (see “Monotheism in the Quran“)
Muslims often hold up one finger to represent their belief in “strict monotheism”:
- It is important to understand that God gradually revealed Himself over time, Before the coming of NT redemption, human beings knew God less fully. This deficiency is not an incidental fact arising merely from some mental or moral deficiency in the individual or the society. It is an inevitable consequence of the very structure of history and the structure of redemption. Human knowledge of God can grow only in step with the redemptive operations that work out God’s plan. Consequently, God’s Trinitarian character is only dimly revealed and dimly understood in the OT. Trinitarian theology in its full form rests on NT revelation (Vern Sheridan Poythress, “Reforming Ontology and Logic in the Light of the Trinity: An Application of Van Til’s Idea of Analogy”; Westminster Theological Journal Volume 57:214).
- In Exodus 3:1-6 the Angel of the LORD appears to Moses in the burning bush and tells Moses to take off his sandals because he was standing on holy ground. The Angel of the LORD identifies Himself in Exodus 3:6 with the God of Abraham, Isaac, and Jacob. He also reveals His name as Yahweh (Exodus 3:13-16; 4:1-5). Yahweh gradually revealed Himself in ways that are not compatible with the Unitarian monotheism of the Quran.
One of the stumbling blocks for Muslims about Jesus’ teaching in the four gospels is that the Qur’an mentions a non-existent book revealed to Jesus from heaven and that Jesus gave to His disciples, the Injeel (al-injīl; cf. Qur’an 5:46-47; 57:27). Jesus was never given a book from heaven and Jesus never gave a book to His followers. See “What every Muslim should know about the Bible.“
- Jesus’ title “Christ” refers to Jesus’ relationship to the Holy Spirit, the Third Person of the Trinity (see 1 Samuel 16:13; John 1:32-34; 20:22; Acts 2:33-36). To believe Jesus is the “Christ” is to believe in Jesus’ death on the cross, His resurrection from the dead, and His ascension to the right hand of God the Father (Matthew 16:13-23; Acts 2:32-36; 1 Peter 1:3; 3:21-22).
- “Some have suggested that the Qurʾān refutes heretical Christian beliefs (e.g. tritheism, adoptionism, the physical generation of the Son) rather than the orthodox doctrines of the Trinity, Incarnation, etc. In practice, however, the vast majority of Muslim commentators have assumed that the Qurʾān does refute the Trinity, the Incarnation, and the Christian doctrine of divine sonship, especially as these are understood to contradict the central Islamic tenet of the oneness of God” (Kate Zebiri, “Polemic and Polemical Language”; Encyclopaedia of the Qurʾān. General Editor: Jane Dammen McAuliffe . Brill [Leiden and Boston], 2005. CD-ROM version).