For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord.
(Romans 6:23 NIV)
We cannot appreciate the magnitude of God's gift of eternal life until we first understand that the wages of sin are death. Wages are what we "earned," what we "deserve." "Death" is not only physical death, here, but spiritual and eternal death. Our sin was an offence to the infinitely holy God, and thus justly deserved eternal punishment. But God's grace, which was greater than all our sin, brings us eternal life instead.