Christians are monotheists; as is Jesus (Mk. 12:29); as are the demons (Jas. 2:19); and as were the Jews of the Old Testament (Deut. 6:4). Throughout history Jewish synagogues have resounded with the statement “The LORD our God, the LORD is one” (Deut. 6:4b ESV). This foundational confession of true Judaism, affectionately referred to as the Shema, was not only precious to Old Testament Jews, it is likewise precious to New Testament Christians. Trinitarian Christians echo that verse and go on to quote the apostle Paul who said, “there is no other God but one” (1 Cor. 8:4c). So before explaining how the God of the Bible exists eternally in three distinct persons (Father, Son, and Holy Spirit) we do well to affirm that He is one is essence. The distinction of personalities does not imply distinctions of deities; there is only one God. There is not a smorgasbord of options. Nor is there a pantheon of divine beings. The mythology of ancient Greece and the polytheism of modern day Hinduism stand opposed to this central tenet of the Christian faith. There is only one God who is to be loved with all of a person’s heart, mind, soul, and strength (Deut. 6:5).

It may not seem like this doctrine is under steady assault but it can become one that we take for granted; and as result, we may be intellectually orthodox and yet ethically sloppy. Doubtless, one of the reasons why the LORD so often reminded the people of Israel that He was the only God was not only so they would forsake the polytheism of the pagans but so that they might look to Him as their only Savior (Isa. 43:10-11). The two essentially went together – ‘stay away from them; and stay close to Me.’ The pronouncement of monotheism, then, was oftentimes connected to a call to God’s people for fidelity (cf. Deut. 4:35-41). The apostle John reminds Christians that we need the same kind of reminders with the closing words of his first epistle: “Little children, keep yourselves from idols. Amen” (1 Jn. 5:21). The doctrine of monotheism is a reminder to us that our God will not tolerate double-heartedness. Yahweh will not share a throne with Baal or Mammon or any other contender to the throne of a person’s affections.

If we have truly heard the Shema we will love the one true God (Deut. 6:4-5), treasure His words in our heart (v.6), find His revelation to be a regular reflection, seek for it to be a routine part of familial conversation (vs.7), and, by God’s grace, we will have it always before us, affecting the way we live (and see) life around us, both inside and outside of the home (vs.8-9).

And the Scripture makes it clear: to truly love this one true God necessarily involves loving the Son that shares His essence. Being a monotheist does not preclude someone from being an idolater. Idolaters can come in many forms, including monotheists. So while the New Testament undoubtedly upholds the monotheism of the Old Testament, it makes clear that one cannot worship the God of the Old Testament without confessing, knowing, loving, and trusting in the person and work of the Lord Jesus Christ (Mt. 10:32-33; Jn. 8:42; 17:3; Acts 16:31; Cor. 15:3-4; Jn. 2:23; 5:11-13, 20). To deny the Son is to not have the Father (1 Jn. 2:23a); but to confess the Son, as the one who is Lord (Rom. 10:9) and Savior (1 Jn. 4:4), not only glorifies the Father (Phil. 2:11) but is an essential piece of evidence that a person has that God, the-God-who-is-one (Deut. 6:4), as his father (1. Jn. 2:23b).