The Trinity is shirk

Christian faith begins with the same confession as Jewish faith: “Hear, O Israel: The LORD our God, the LORD is One” (Deuteronomy 6:4). When Jesus was asked which commandment was most important, he quoted those words (Mark 12:29). No Christian church teaches that there are three gods.

Some popular objections, and some readings of the Qur’an, target ideas that Christians reject as firmly as you do.

• The Qur’an pictures God asking Jesus, “did you say to the people, ‘Take me and my mother as deities besides Allāh?’” (5:116). Some early interpreters, reported by Ibn Kathir, read “third of three” (5:73) the same way. No mainstream church has ever taught that Mary is God or part of God.
• It asks how God could have a son “when He does not have a companion” (6:101). Christians agree that God has no consort and did not father a child in any physical way.
• Christians do not believe God is one member of a group of three gods.

Clearing this ground does not answer your objection. The Qur’an also says, “Exalted is He above having a son” (4:171), and Ibn Kathir’s commentary on that verse describes the councils and churches that confessed Jesus as divine and rejects them all, not only a crude picture of a divine family.

Christians do not think of the Trinity as an addition: God, and then two others beside him. They believe there is one God, one divine being with one will and one nature, and that this one God exists eternally as three persons, the Father, the Son, and the Holy Spirit. “Person” here does not mean a separate being, as three human beings are three separate beings. It names a distinct relation within the one God. And by “Holy Spirit” Christians do not mean the angel Gabriel, as Muslims understand Ruh al-Qudus, but God’s own Spirit.

“Son” is the word that gives the most offense. The Nicene Creed, the fourth-century statement of faith that most churches still recite, says the Son is “begotten, not made.” Christians use “begotten” for an eternal relationship, not a physical birth: the Son is from the Father as a word is from the one who speaks it, with no mother and no beginning.

Islam rejects divine sonship in that sense too. Muslim scholars read “He neither begets nor is born” (112:3) as a denial that God has any son at all, and Ibn Kathir’s commentary on 4:171 discusses the council under Constantine where the creed was first written. So you can understand exactly what Christians mean and still judge that it breaks God’s oneness.

Shirk is associating partners with God: setting up anything as a rival, an equal, or a second god beside him, in his being, his rule, or his worship. Christians agree that this is the gravest wrong. Their claim is that the Son and the Spirit are not partners beside God, because they are not other beings. They are the one God’s own Word and Spirit, sharing his one being, not added to it.

You may reply that this is a distinction without a difference. Christians think the difference is real. A partner is someone outside God who shares what is God’s. Oneness rules that out completely. Whether oneness also rules out every distinction within God is a further question, and Muslim theology has faced a form of it. Sunni teaching holds that the Qur’an is God’s uncreated speech, eternal with him, and that this does not divide him. Muslim scholars distinguish an eternal attribute from a person. Christians are asking a related question: can God’s eternal Word be with him and be him without becoming a second god?

The Qur’an itself calls Jesus “His word which He directed to Mary and a soul [created at a command] from Him” (4:171). Ibn Kathir reads this as the creating word “Be,” and insists that “from Him” does not mean part of God. Christians read the same language as pointing to the eternal Word. That is where the two faiths part, and it comes down to who Jesus is.

The Trinity was not imported later by Greeks who were used to many gods. Jesus’ first followers were Jews who would have died rather than worship an idol.

Within twenty years of Jesus’ death, Paul, a former Pharisee, rewrote Israel’s confession of one God this way: “there is but one God, the Father, from whom all things came… and there is but one Lord, Jesus Christ, through whom all things came” (1 Corinthians 8:6). He did not add a second god. He placed Jesus inside the confession of the one God. The scholar Richard Bauckham, in Jesus and the God of Israel, calls this including Jesus in the unique identity of God.

John’s Gospel opens the same way: “In the beginning was the Word, and the Word was with God, and the Word was God… Through Him all things were made” (John 1:1). The one through whom all things were made is not one of the things made. Larry Hurtado’s Lord Jesus Christ traces how Jewish believers prayed to Jesus and sang to him from the earliest years, while still refusing every other god.

You do not need to accept these writings as Scripture to see what they show: the earliest Christians believed they were keeping the confession of one God, not leaving it. The doctrine of the Trinity, worked out over the following centuries, was the church’s attempt to say both things at once: God is one, and Jesus belongs within that one God.

This page does not show that the Trinity is true, or that Christians have answered your objection. What it does show is narrower: the Trinity is not three gods, and Christians do not intend to set up a partner beside God. They believe they are worshiping the one God and no other.

Whether that belief holds depends on two questions that Islam and Christianity answer differently. The first is whether distinct persons within the one God are compatible with his oneness. The second is who Jesus is. If Jesus was a created messenger, the charge of shirk stands. If he is the Word through whom all things were made, Christians believe it does not. The second question can be examined from the earliest sources about him. The Christian case is set out in Jesus is God.