Deuteronomy 19 opens with a discussion regarding the cities of refuge that God sets up in each region. These are places where those who have killed someone by accident may flee.  Those who commit a wrong intentionally, on the other hand will be put to death.

Deuteronomy 20 deals with battles the Israelites will fight in the future. They should receive a blessing from a priest before entering into battle. If they are distracted by an issue at home they should not engage in battle. If the nation surrenders to them peacefully they are allowed to take the people as slaves. However, if they must fight their enemies they are to kill all the men and take the women and children and all the possessions as the spoils of war. This statute is only pertinent to battles in the future and far away. The Israelites are charged to annihilate the nations they are conquering in the Promised Land so that they will not teach them about things that are abhorrent to God.

In Romans 4 Paul is dealing with the arguments the Jews have been making that the Gentiles must obey the law, particularly the ordinance that they should be circumcised in order to receive God’s grace. He uses Abraham as his example stating that Abraham was not justified by his works; rather he was reckoned righteous because of his faith. He was reckoned righteous before he was circumcised. He received the sign of circumcision as a seal of righteousness to attest to the faith he had before he was circumcised. Circumcision wasn’t the cause of the righteousness it was given because of the righteousness.  He believed in God and God’s promises even when the physical evidence should have convinced him otherwise.