What does the Bible say about God's oneness? 

The Bible passages below can be used in sermons, prayers, pastoral care, or worship planning focused on God's oneness. 

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  Deuteronomy 6:4, the Lord is one (the Lord is God, the Lord alone)
• Isaiah 43:10-11, no savior but God (no other god before or after me)
• Isaiah 44:6, no god besides me (the first and the last)
• Hosea 13:4, no savior but God (you know no God but me)
• Zechariah 14:9, the Lord will be one (king over all the earth)
• Matthew 23:9, one Father (the one in heaven is your only father)
• Mark 12:32, he is one (besides him there is no other)
• John 10:30, unity of Father and Son (Jesus says he is one with the Father)
• John 17:20-22, unity of Father and Son (Jesus expresses oneness with the Father)
• 1 Corinthians 8:4-6, there is one God (no God but one)
• Ephesians 4:5-6, one God (one Lord, one faith, one baptism)
• 1 Timothy 2:5, one God (one God, one mediator)
• James 2:19, God is one (even the demons believe this) 

Sermon ideas about God's oneness 

What do Christians mean when they say they believe in one God? Sermons on God's oneness can examine at least three things. 

One Father 

First, a sermon on God's oneness can show that there are contexts in which God means the Father. This is a deep and usual New Testament use, especially characteristic of the "one God" texts that reflect Deuteronomy's Shema ("Hear, O Israel . . ." in 6:4) and the general prophetic tradition of exclusive monotheism (for example, in Isa. 43 and 44 above). 

When the Shema is heard in the New Testament, the one God is either directly or indirectly identified as the Father. This identification occurs indirectly when in Mark 12:29 and John 17:3 Jesus is identified as the Son of Man, or the Son absolutely, over against this one God. And it occurs directly in 1 Corinthians 8:6, where Paul identifies the one God with the Father and distinguishes him from the one Lord, who is Jesus Christ. 

In keeping with this biblical use, there is an old Christian habit of assigning some priority for the use of God to the first of the three trinitarian persons. This is, for example, the only way God is used in the Apostles' Creed. By the time of the Reformation, John Calvin has in mind the whole Latin tradition of the Father as "the fount of Divinity" when he suggests that "the name of God is peculiarly applied to the Father." The tradition may also be found in Augustine's De Trinitate (4. 20. 29) and in Thomas Aquinas' Summa Theologica (1. q. 33, arts. 1-3). 

One divine essence 

A second traditional concept is the use of God for the divine substance or essence, possessed wholly by the three divine persons. God's essence is God's God-ness, or Godhood, the group of properties (omnipotence, omniscience, supreme holiness, perfect goodness, perfect justness, and so on) that are severally necessary and jointly sufficient for a trinitarian person to be divine. 

Calvin says, "When we profess to believe in one God, under the name of God is understood a single, simple essence in which we comprehend three persons." Father, Son, and Spirit are each and all divine. When we say, "the Father is God, the Son is God, and the Holy Spirit is God," God means wholly divine. 

One divine society 

Third, the sixteenth verse of the Athanasian Creed presents another appropriate use of the word God. If the author is as much of an Augustinian as is usually thought, the relevant source for interpreting him is Book 5 of the De Trinitate, where Augustine clearly uses God not for the Father, as he did here and there in Book 4 (where the preexistent Son of God is in view); nor only for the divine essence; but also for the Trinity. 

He says this: "For as the Father is God, and the Son is God, and the Holy Spirit is God, which no one doubts to be said in respect to substance, yet we do not say that the very supreme Trinity itself is three Gods, but one God." The claim that "the Trinity is one God" appears a number of times in Book 5. 8-11. 

In this case, the name God would be a common or, better, a communitarian term that is applied first of all to the divine community as such and then to the three distinct members of that same community. Inside it, the Father is metaphysically underived, but the Son derives from the Father—not in time but in some mysterious, quasi-genetic respect that makes it appropriate to call the first person the Father and the second person the Son. Meanwhile it appears that the Holy Spirit is not a family member but the agent of the Father and the Son. 

Overall, in a sermon on God's oneness, we may conclude that there are three divine persons, but only one Father and only one divine essence and only one Trinity or divine society. 

Excerpts about God's oneness 

• "Ephesians 4:4-6 clearly lines up with the Jewish confession of one God. Yet, at the same time, the passage speaks of the Spirit, the Lord, and the Father as if the three were all divine, all in some way one true God." Discussion Questions, Scripture Meditation or Sermon by Mark D. Roberts from Theology of Work  

• "That God is One (and not divided) is the very foundation for all rationality and sanity. That God is undivided and consistent within assures you that two plus two will always be four – and that you can anchor your sanity on that." Article about Theology by Ronald Rolheiser from Catholic Archdiocese of Edmonton  

• "When Moses told the people of Israel that their God was one, he was not primarily affirming a truth about God's relationship to other gods. He was affirming a truth about God's heart. He was telling them that God's heart was undivided, that God was fully present to them. God's oneness of heart was Moses' way of defining the meaning of God's love." Scripture Meditation or Sermon by Tom Boogaart from Reformed Journal