The objection
God speaks as “I” and declares that there is no God besides him. If YHWH is Israel's one God, any personal plurality within God seems excluded.
1. God's uniqueness is the starting point
Deuteronomy 6,4 binds Israel to YHWH alone. Isaiah 44,6–8 and 45,5–7 exclude every divine competitor. The Trinity does not weaken these statements. Father, Son and Spirit are not three beings of whom one is the highest God. The one God is Father, Son and Spirit.
The additional sentence “One God must be exactly one person” appears neither in the Shema nor in Isaiah's polemic against idols. It is the premise of the Unitarian inference. The word “one” by itself does not decide how God's unity is personally determined. Nor does the Hebrew echad already prove a composite or triune unity. God's entire self-revelation is decisive.
2. The New Testament does not place Jesus alongside YHWH
Isaiah 45,23 announces that every knee will bow before YHWH. Philippians 2,10–11 takes up this confession and applies universal homage to Jesus Christ. No rivalry with the Father arises: Christ's honor occurs to the glory of God the Father. Paul does not increase the number of gods. He confesses Jesus within the unique divine dominion.
Hebrews 1,10–12 is clearer still. The letter applies words from Psalm 102 to the Son: He founded heaven and earth; creation passes away, he remains. The original psalm is addressed to YHWH. The Son is therefore not merely given an honorable title, but distinguished as the enduring Creator from perishable creation.[1]
3. The divine I is not divided into three gods
If YHWH declares in Isaiah 44,24 that he alone is Creator, and John 1,3 attributes all creation to the Word, two possibilities remain: Either the texts contradict one another, or the Word is no alien collaborator outside the one God. The Christian conclusion is the second. The Creator's unity is precisely the reason not to treat the Son as an additional lesser god.
A singular pronoun designates the one speaking God. It is not an exhaustive treatise on the personal relationships of his being. Whether the Father, the Son or God without further personal specification speaks must be clarified in each text. The mere form “I” cannot replace this exegesis.
4. Progress in revelation is no change of God
The New Testament proclaims no different God from the Old. It shows who Israel's God is in his eternal fullness. The apostles can therefore confess Israel's monotheism and call on Jesus as Lord simultaneously. They treat Jesus' deity not as an exception to God's uniqueness, but as part of its rightly understood meaning.
Anyone arguing from Isaiah against Jesus' deity must therefore explain why the apostles apply precisely Isaiah's YHWH texts to Jesus. The singular alone does not answer this question.
5. Does undivided unity exclude every relationship?
The stronger objection from simplicity claims: Every real distinction in God must make him composite. Yet “distinct” and “composed as a constituent part” do not mean the same thing. The classical Trinitarian answer does not understand Father, Son and Spirit as three pieces that combine into God. Being Father and being Son distinguish their relationship to each other; they distribute neither God's power nor his being among several bearers.[3]
This does not yet spell out the philosophical explanation in every detail. But the decisive transition becomes visible: Anyone inferring God's unipersonality from his undividedness must show why real personal relationship would necessarily be division. The Shema does not say this. The Christian answer preserves his undivided unity while taking the relationships attested in the New Testament seriously.
Biblical texts in context
Sources and further study
- Robert L. Reymond, A New Systematic Theology of the Christian FaithCh. 8, “Old Testament Yahweh Passages Applied to Jesus,” pp. 311–312.
- John M. Frame, The Doctrine of GodCh. 28: Jesus' deity within biblical monotheism.
- Thomas Aquinas, Summa theologiaeI, q. 28, a. 2–3: real relationships without composition of divine being. The relational model explains the Christian answer to the objection from simplicity.