"How can someone's finite sins earn infinite punishment?"
In the opening chapter of his book, "The Pleasures of God", John Piper presents the deep pleasure -- complete, fulfilled pleasure -- God the Father has for Jesus the Son, beginning with 1Tim 1:11, "The good news of the glory of the happy God." And at his baptism, the Father said, "This is the Son of my great pleasure."
It strikes me how painful it must have been for the Father -- who loves the Son completely with an incomparable love -- to crush His Son for the sake of sinners; the dearly loved Son who deserves only glory, not shame.
How much must God love -- not with the same kind of love as He has for the Son, but with a love that is more like "pity" -- sinners (you and me) that He would crush, with the weight of His full vengeance, His Son whom he loves so completely?
Yet, it somehow pleased God to crush the Son (Isaiah 53:10) in the place of sinners. But how could God find any pleasure in doing so to the One He loves for lost, broken, desperate people like us?
The Son pleased God in that he was the perfect, sinless, beautiful Lamb of Sacrifice who was qualified to bear the full measure of wrath stored in the Father's cup. And when the Father poured it out on him, how painful must it have been that He would turn His head and look away from His brutalized Love on the Cross...
...and not answer His Son's cries.
That, my friends, is how much God loves -- pities -- you and me. The thought is unfathomable. Oh, how much grace is bestowed upon the sinner who places his hand in the bosom of the so-loved Son of the Father! But how much vengeance is heaped upon the fool who rejects this dearly loved Son (Heb 10:29).
The skeptic asks, "How can someone's finite sins earn infinite punishment?" Because he has rejected the Son of the Almighty -- the perfect, sinless, beautiful One whom the Father so adores. And the Father has declared that is sin worthy of eternal punishment.