When Jesus was crucified on the cross, He identified with our fallen humanity, and took all on our sin himself paying the price for it.
“In Him we have redemption through His blood, the forgiveness of sins, according to the riches of His grace” Ephesians 1:17.
When we have God’s forgiveness for our sins, we have redemption; we are redeemed. Redeem means “to buy back” or “to ransom.”
When a person is a slave, he or she has no choices. When slaves were sold in the market place in Jesus’s day they had to stand on a block, and from a post behind them a spear was extended over there head. The apostle Paul said “I am carnal, sold under the spear of sin, which is extended over my head. I have no options. “I am carnal, sold under sin”
The good news is that Jesus Christ walked into the slave market and said,
“I’ll buy him; “I’ll buy her, I’ve paid the price for them. They are now My son and daughter.” That is redemption and it’s free to all who call on the Name of Jesus.