Introduction: The Polemical Challenge
When unitarian apologists (such as Muslim debaters or Iglesia ni Cristo polemicists) cite John 17:3 (“that they may know You, the ONLY true God”), they frequently argue that the term “ONLY” (Monos in Greek, Yachid in Hebrew) strictly excludes Jesus Christ and the Holy Spirit from being true God, limiting deity exclusively to the Father.
However, a careful examination of scriptural precedent demonstrates that the word “ONLY” in biblical usage does not always mean “singly to the total exclusion of any other.” Instead, it frequently denotes an exalted, unique, beloved, or primary covenantal position.
Part I: The “Isaac Precedent” (Genesis 22 & Hebrews 11)
Consider God’s command to Abraham in the Old Testament:
Genesis 22:2: “Take now your son, your only son Isaac, whom you love, and go to the land of Moriah, and offer him there as a burnt offering...”
Genesis 22:12: “...now I know that you fear God, since you have not withheld your son, your only son from Me.”
Genesis 22:16: “...because you have done this thing, and have not withheld your son, your only son...”
Hebrews 11:17: “By faith Abraham, when he was tested, offered up Isaac, and he who had received the promises offered up his one and only son [monogenēs].”
The Crucial Question:
Does calling Isaac Abraham’s “only son” negate or erase the historical truth of Genesis 16:15?
“So Hagar bore Abram a son; and Abram named his son, whom Hagar bore, Ishmael.”
Clearly not! Ishmael was physically and chronologically Abraham’s firstborn son. Yet God repeatedly called Isaac his “only son.”
Why Was Isaac Called “Only”?
Unique Covenantal Status: Isaac was the child of promise, divinely foretold when YHWH appeared in human form to Abraham (Genesis 18) when Abraham was 99 and Sarah was 90.
Messianic Lineage: The promised “Seed of the Woman” (Genesis 3:15) who would crush the head of the Serpent—and through whom all families of the earth would be blessed (Genesis 12:1–3)—was decreed to come exclusively through Isaac, not Ishmael.
Beloved Position: The word Yachid / Monogenēs here highlights an unparalleled, uniquely beloved status, not numerical solitary existence.
APOLOGETIC TIP: When an opponent quotes John 17:3 to claim the Father is “singly and exclusively” the only God to the exclusion of Christ, ask them: “Was Isaac the ‘one and only’ son of Abraham in an absolute numerical sense?” The Isaac precedent proves that “only” designates unique, supreme honor rather than mathematical isolation.
Part II: Other Scriptural Uses of “Only” (Yachid)
The Old Testament consistently uses Yachid (”only, beloved, precious”) to express deep affection and unique value:
Proverbs 4:3: “When I was my father’s son, tender and the only one [yachid] in the sight of my mother...” (Solomon had other brothers through Bathsheba, e.g., 1 Chronicles 3:5, yet he was uniquely cherished).
Amos 8:10: “...I will make it like mourning for an only son [yachid]...”
Zechariah 12:10: “...they will look on Me whom they pierced. They will mourn for Him as one mourns for his only son [yachid]...”
Part III: Distinction and Shared Divine Glory (Jude 25 & Titus 2:13)
John 17:3: “And this is eternal life, that they may know You, the ONLY true God, and Jesus Christ whom You have sent.”
Galatians 3:20: “Now a mediator does not mediate for one ONLY, but God is one.”
1 Timothy 6:14–15: “...until the appearing of our Lord Jesus Christ, which He will manifest in His own time—He who is the blessed and ONLY Potentate, the King of kings and Lord of lords...”
Jude 25: “To the ONLY God our Savior be glory, majesty, dominion and power, through Jesus Christ our Lord, both now and forever. Amen.”
Analyzing Jude 25 and Titus 2:13:
While Jude 25 distinguishes between the “Only God” and “Jesus Christ our Lord,” other New Testament passages explicitly bestow the exact title of God and Savior upon Jesus Christ:
Titus 2:13 (NKJV): “Looking for the blessed hope and glorious appearing of our great God and Savior Jesus Christ...”
Does Christ Share the Father’s Pre-Existent Glory?
Isaiah 6:1–10 cf. John 12:37–41: Isaiah saw YHWH high and lifted up in His heavenly temple (Isaiah 6). Apostle John explicitly testifies in John 12:41 that Isaiah was beholding the pre-incarnate glory and majesty of Jesus Christ.
John 17:5: Jesus prayed, “And now, O Father, glorify Me together with Yourself, with the glory which I had with You before the world was.”
John 5:23: Jesus commanded that “all should honor the Son just as they honor the Father. He who does not honor the Son does not honor the Father who sent Him.”
Part IV: Lexical Definitions & The Nature of Deity
According to standard unabridged dictionaries (e.g., Webster’s Dictionary, p. 373):
ONLY (Adjective): Alone of its kind; single, sole; unique.
ONLY (Adverb): Solely, merely, just, not more than.
ONLY (Conjunction): Except that, but.
The Shared Essence (Likas na Kalagayan) of the Triune Godhead:
Do the Father, the Son, and the Holy Spirit share the exact same nature, essence, and level of divine existence? Yes.
Creators: Father (Genesis 1:1), Son (John 1:1–3; Colossians 1:16; Hebrews 1:10), and Spirit (Genesis 1:2; Job 33:4) are all active Creators.
Life-Givers: All Three Persons naturally possess and impart eternal life.
Attributes: All Three are omnipotent, omnipresent, and omniscient.
They share the same uncreated substance, divine nature, and divine essence (likas na kalagayan).
Conclusion
The word “ONLY” in Scripture is not a rigid mathematical boundary used to strip Christ or the Holy Spirit of their inherent deity. Just as Isaac was called the “only son” because of his unique, beloved, and exalted covenant position without denying Ishmael’s existence, the title “Only True God” exalts the uncreated nature of Deity above all false, created pagan idols.
Jesus Christ is co-eternal, co-equal in nature, and shares the same divine essence with the Father and the Holy Spirit—the One True Triune God.