“If a man has committed a sin worthy of death and he is put to death, and you hang him on a tree, Deuteronomy 21:22
Why did Jesus have to die on a cross? This is probably the first question that comes to mind when you first discover Jesus. To understand this, you first need to understand Sin and its consequences. Under the Moral Law of God, the wages of sin is death.
The penalty to be hung on a tree was fulfilled when Christ was crucified to the cross. Jesus took your place on that tree!
for all have sinned and fall short of the glory of God, being justified as a gift by His grace through the redemption which is in Christ Jesus; Romans 3:23-24
We are all guilty of Sin, breaking Gods Moral Law, and the penalty for that Sin is death. However because God is full of Love and Mercy, Jesus took our place and became our atoning sacrifice for our Sins. Because of his atonement, we are justified before God, this gift from God is called Grace
But when the fullness of the time came, God sent forth His Son, born of a woman, born under the Law, so that He might redeem those who were under the Law, that we might receive the adoption as sons. Galatians 4:4-5
Jesus became Flesh, born of Mary, born Under The Law. Even though Jesus committed no sin, he bore the penalty for our sins. In order for Jesus to Fulfill The Law (Matthew 5:17) he has to be Under The Law. Because Christ defeated Sin and death and rose after 3 days, we can now be Children of God Amen!
Who his own self bare our sins in his own body on the tree, that we, being dead to sins, should live unto righteousness: by whose stripes ye were healed. 1 Peter 2:24 (KJV)