Jesus was a perfect man, the corresponding ransom for Adam. Adam was
perfect and lost perfection through sin; Jesus was perfect and gave
up His perfect human life to redeem Adam's offspring. The ransom is a
precise legal exchange — one perfect human for one fallen human and
his line.
This isn't primarily an argument for the deity of Christ — it's an argument that the JW ransom mechanism doesn't work without it. Walk through the math. (1) The "corresponding ransom" theory says Jesus ransoms Adam's offspring because Jesus equals Adam in nature. But Adam's progeny is billions of souls across thousands of years. One perfect human life as a price for one perfect human life ransoms Adam — not necessarily Adam's billions of descendants. (2) — the blood of Christ has eternal redemptive efficacy because it is offered "through the eternal spirit." That is divine, not merely creaturely, language. (3) (NWT footnote) — "purchased… with the blood of his own [Son]." The Greek genitive construction is striking; some manuscript traditions read simply "with his own blood" — God's blood. (4) calls Jesus' blood "precious" with the kind of value that "imperishable things like silver and gold" cannot match. The implication is that the blood's worth exceeds creation. Then ask: a perfect MAN dying for one man (Adam) is symmetric. A perfect MAN dying for billions is not symmetric — UNLESS the value of that one life is infinite. And only one kind of life has infinite value: divine life.
A perfect-man-for-Adam ransom only mathematically covers Adam, not Adam's billions of offspring. The ransom only "scales" if the value of the sacrifice is infinite — and only the eternal God-man can offer an infinitely valuable sacrifice. The Watchtower's "corresponding ransom" doctrine quietly assumes the very thing it denies: the divine worth of Christ's blood.
Jesus' perfection makes His sacrifice valuable enough.
Then your math is symmetric: one perfect man's life pays for one perfect man's loss — that is, Adam. Where does the additional coverage for Adam's billions of descendants come from? You can't ransom one perfect life and walk away with billions of redeemed souls unless the ransom price is greater than the equivalent. The Watchtower's literature appeals to the idea that Jesus' blood "corresponds" to Adam — that's exact equivalence. Equivalence cannot exceed itself.
The corresponding ransom is symbolic — Jesus' obedience is what counted.
says it bluntly: "without the shedding of blood there is no forgiveness." This is not symbolism. And gives the reason the blood is efficacious: "Christ, who through an everlasting spirit offered himself unblemished to God." "Everlasting spirit" attached to the One offering — that is divine self-description, not angelic-being-doing-his-job.
Acts 20:28 has manuscript variants — the NWT renders it 'blood of his own Son.'
Let's grant the variant. Even "the blood of his own Son" still carries the shock that GOD purchased the church through this blood — meaning the price-payer is divine even if the price-bearer is the Son. But notice — the textual tradition that reads simply "with HIS OWN BLOOD" (referring to God) is supported by the oldest manuscripts (Codex Vaticanus, Codex Sinaiticus original). Even the NWT footnote acknowledges this. The early church read this verse as God paying with God's own blood.
We're getting too philosophical. The ransom is enough — Jehovah accepted it.
Fair — let me make it concrete. Imagine your son broke a window worth ten dollars, and you paid the neighbour ten dollars in restitution. That's a corresponding payment. Now imagine your son broke ten thousand windows, and you paid ten dollars. That is not corresponding — that is hopelessly inadequate, unless that ten-dollar coin is somehow infinitely valuable. The Watchtower's ransom theology requires Christ's life to either equal Adam (in which case it can't ransom Adam's billions) or exceed Adam (in which case His worth is more than human). There is no third option that fits the texts.
Don't accuse JWs of "selling Jesus short" or use words like "diminishing." Stay with the maths. The asymmetry between one-man-for-Adam and one-man-for-billions does the work itself if the JW lets the question sit.
Read in the NWT. Notice every adjective attached to Christ's blood and self-offering — "everlasting redemption," "eternal spirit," "unblemished." Ask: does this language fit a created-being sacrifice, or does it require divine worth?