“When the time came to completion, God sent his Son, born of a woman, born under the law, to redeem those under the law, so that we might receive adoption as sons.” - Galatians 4:4-5 CSB
The story of Jesus is a beautiful one that tells of redemption for all people that believe in him. Reading this passage simply identifies how and why that work was done for us, so that we might be adopted into God’s family, not as outsiders, but as joint heirs to the Kingdom of Heaven with Christ Jesus Himself.
The Old Testament Law carried with it such weight of living a holy life that had to constantly be redeemed through sacrifices and offerings because we as people are not capable of keeping every aspect of that law. Jesus was thus born under the same law that we are born under and as God Himself in the flesh, lived a spotless life that we could and would not. This allowed His ultimate act of love at the cross to be payment to God the Father for all sin of all mankind forevermore, to set us free from slavery to sin and the law, that we might be accepted into that joint heir status with Christ Jesus. No matter who you are, where you are, what you have ever done, this joint heir status is yours as well by believing in Christ Jesus.