Question: Do you have to believe in the Trinity in order to be a Christian? I’m not a believer in this “man made” doctrine.

Answer: Thanks for your email and your question about the Trinity. We appreciate your honesty regarding your position, but we must respectfully disagree with you.

To deny the Trinity is to embrace the “modalism,” which is the belief that there is just one God, and that he manifests himself in three different modes or forms at different times. This view, which has been around since the third century (when it was also known as “Sabellianism” after one of its leading advocates), and is held in our day by such groups as the Oneness Pentecostals and “Jesus only” groups, is considered “heresy.” That is, it does not line up with the orthodox (or “correct”) teaching of the Bible.

Why is modalism heresy? What’s wrong with thinking of God as one person who simply expresses or manifests himself in different modes or roles? Probably the main reason is that this view goes against the teaching of Scripture. The Bible clearly presents one God in three persons. This isn’t tri-theism. That would be polytheistic. It’s tri-unity. And it isn’t something “man made.” It is entirely biblical.

To use a common example people sometimes erroneously give as an illustration of the Trinity, let’s say that God is like a man who at various times is a father, a husband, and a son. Why can’t God be like that? Because in Scripture more than one person of the Godhead is often seen simultaneously and often interacts with One another (examples: Genesis 1:26; 3:22; 11:7; Psalm 2:7; 104:30; 110:1; Matthew 28:19; John 14:16). As a father and a son, you can have a conversation with yourself, but you can’t interact with yourself. It takes more than one person to be in community, as God the Father, God the Son, and God the Holy Spirit are.

The other sticky problem with modalism is that you can’t account for the saving death and resurrection of Jesus Christ. If you have just one God in different roles, then Jesus didn’t truly die, because God couldn’t die. But God in the person of Christ, who is himself fully God and fully human (another important doctrine that has come under fire through the centuries), can die for humanity and satisfy God’s perfect requirement.

We think it’s great you are thinking through these issues, and that you are asking questions. They aren’t easy to think about, but they are important.

May God in three Persons–Father, Son and Holy Spirit–bless you!