God must pay our wages. He has to in order
to be consistent with His principles, which
are His righteousness and holiness.

God owes us something, and that is death.
He must pay the debt. He will pay it in full,
"the soul that sinneth, it shall die"!

But Jesus, who had no sin, ran in between
the human race and the death penalty and
bore it for us. God, having made His Son
suffer the full penalty for sin, can then
justly pardon us.