For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God.  II Corinthians 5:21

This is the what and the why of our lives.
He became sin — so that we might become His righteousness.
He took on death — so that we might have life.
He took our place — so that our lives would take on glory and holiness and action that brings forth God’s Kingdom.