Why? Because a perfect sacrifice was required, and only Jesus fit the bill. 2 Corinthians 5:21 tells us that “for our sake” God the Father made His Son Jesus who knew no sin – He was perfectly righteous, the spotless lamb of God – to be sin. All of the sin – past, present, and future – of adulterers, perverts, degenerates, drunkards, prostitutes, gangbangers, self-righteous, liars, crooks, murderers, and — you fill in the blank on Jesus and He bore it on the Cross lovingly out of obedience for you and me.
He did it so that “in Him we might become the righteousness of God.” Spurgeon writes:
All the love and the acceptance which perfect obedience could have obtained of God, belong to thee, because Christ was perfectly obedient on thy behalf, and hath imputed all his merits to thy account, that thou mightst be exceeding rich through him, who for thy sake became exceeding poor. Oh! how great the debt of love and gratitude thou owest to thy Saviour! "A debtor to mercy alone, Of covenant mercy I sing; Nor fear with thy righteousness on, My person and offerings to bring: The terrors of law and of God, With me can have nothing to do; My Saviour’s obedience and blood Hide all my transgressions from view."
Have you thanked Jesus today?