Is the death penalty fair? Why would a loving God tell people to stone each other to death? What happened to “turn the other cheek”, why is there a life for a life? Doesn’t God believe in forgiveness and second chances?
The death penalty was introduced in Genesis 9:5-6, and it was for murder. Cain, the firstborn son of Adam and Eve (the first humans), committed the very first murder. He murdered his brother Abel in Genesis 4:8. In Genesis 4:9-15, God punishes Cain with hardship in growing crops, and Cain complains his punishment is too much and he is afraid someone else (his parents or siblings) will kill him. So God shows him mercy by branding him with a mark that would function as a symbol of protection in Gen 4:15.
Many years later, in Genesis 4:23-24, Lamech, one of Cain’s sixth-generation descendants, brags about murdering a man and believes that Cain’s mark will be on him too and protect him. I believe that this warping of God’s mercy on Cain created a “Murder Olympics”, where people interpreted the mark of Cain as a reward of special protection. This is likely one of the reasons Gen 6:11 says the world was “filled with violence”. God had to stop this with death. Imagine if God didn’t kick Adam and Eve out of the Garden to prevent them from eating from the Tree of Life and they became immortal in a sinful state (Gen 3:22-23). Then there would be an eternal war between Cain and Abel, and no flood could stop it because the humans would be immortal. In Gen 9:5-6, God then establishes the death penalty for murderers because humans obviously can’t handle the mercy he showed Cain. Seems justified to me. In Deut 17:6 God says that murders must be put to death but only if there is more than one witness. Numbers 35:30-34 says the same and more establishing that no one can exchange the murderer’s death for a ransom. In fact, the murderer’s death can’t even be covered by an animal sacrifice. Murder pollutes the land spiritually and the only way to cleanse the land of murder is to execute the murderer.
People may still wonder, why would God have sinners executed in the old testament but not the new? One has to remember sin spreads like a disease if one person does it then other people will do it. Leaven (yeast) is often used as an analogy for sin (Gal 5:7-10, 1 Corinthians 5:5-7). The death penalty only applied to crimes where people were “caught in the act”, meaning secret sin was judged by God usually with diseases that make people unclean like skin diseases, which is why these diseases required offerings when the person was cured (Lev 14-15). This is what happened to Miriam in Num ch. 12 for badmouthing Moses’ wife. In the case of adultery, the woman was made barren if she was put to the test in the Tabernacle (Num 5:11-31). The distinction is that if a sin is done in secret then God can deal with a person personally and if they don’t repent, their sin is exposed through illness. However, if a crime is public (the guilty are caught in the act by witnesses) then it must be dealt with immediately, otherwise, people will think they can just do whatever they want. There is a death penalty for other things like adultery (Deut 22:22) and idolatry (Ex 32:1-29) because they are covenant violations, and God takes oaths and covenants very seriously. For the sin that wasn’t caught publicly, that should be considered an act of mercy by God giving people time to repent, and then sacrificing to have an animal die in their place. This was necessary because the wage of sin is death (Romans 6:23).
Jesus called himself the bread of life around the time of Passover in John 6:32-59, he was the unleavened bread (or the sinless one). The Israelites ate unelevated that they ate during Passover, and when we take communion it represents the flesh of the unleavened or sinless Messiah. Jesus also represents the Passover lamb since the lamb’s blood covered the Israelites and protected them from death, just like we are covered by his blood. Jesus’ death covered our sin, functioning as a fulfillment of the sacrificial laws, so we don’t need to sacrifice animals or die since Jesus died for us (Heb 10:-18). The Holy Spirit was not inside of those who were under the old covenant to transform their hearts, so God has to stop sin directly because people are naturally too stubborn to change because of our sinful nature. However, in the new covenant, Jesus died in place of our sins including murder, so that we can be made right with God. He took our punishment on the cross (Isa 53:10, 2 Cor 5:21), and therefore we don’t need to die, we instead can simply repent and follow the Holy Spirit.
This does not mean believers can keep on sinning without a care in the world. Hebrews 6:4-8, and 10:19-31 both make it clear that there is condemnation for people that play games with this new covenant. The goal is to be free from slavery to sin (John 8:31-36, Rom 6:6-22), Christ did not die for us to stay trapped by it. Jesus shed his blood to make us ritually pure so that we can receive the Holy Spirit on the inside and the Holy Spirit is what helps us overcome sin nature (Gal 5:16, Gal 6:7-8). Only those who believe in Jesus receive the holy spirit (John 14:15-17, Rom 8:5-11).