Before the Ten Commandments, God specifically singled out as sin deliberately taking another’s life. We find the story in Genesis Chapter 4:
Now Abel kept flocks, but Cain worked the soil. In the course of time Cain brought some of the fruits of the soil as an offering to the Lord. But Abel brought fat portions from some of the firstborn of his flock. The Lord looked with favor on Abel and his offering, but on Cain and his offering he did not look with favor. So Cain was very angry, and his face was downcast. Then the Lord said to Cain, “Why are you angry? Why is your face downcast? If you do what is right, will you not be accepted? But if you do not do what is right, sin is crouching at your door; it desires to have you but you must master it.”
Now Cain said to his brother Abel, “Let’s go out into the field.” And while they were in the field, Cain attacked his brother Abel and killed him. Then the Lord said to Cain, “Where is your brother Abel?” “I don’t know,” he replied. “Am I my brother’s keeper?” The Lord said, “What have you done? Listen! Your brother’s blood cries out to me from the ground. Now you are under a curse and driven from the ground, which opened its mouth to receive your brother’s blood from your hand. When you work the ground, it will no longer yield crops for you. You will be a restless wanderer on the earth.”
By Moses’ time, the Hebrew law specifically set forth that: “Anyone who strikes a man and kills him shall surely be put to death. However, if he does not do it intentionally, but God lets it happen, he is to flee to a place I will designate. But if a man schemes and kills another man deliberately, take him away from my altar and put him to death.” This law fleshed out the simple statement, “You shall not murder”, found in the Ten Commandments.
From these Old Testament texts we find that, unless God gives express permission, He expects us to refrain from deliberately planning to take another’s life.
But what of waging war? The Bible records God clearly directing Israel to dispossess the inhabitants of the “Promised Land.” And that surely means God intended His people to deliberately kill others, correct? Looks that way. According to Deuteronomy:
But in the cities of these peoples that the Lord your God is giving you for an inheritance, you shall save alive nothing that breathes, but you shall devote them to complete destruction, the Hittites and the Amorites, the Canaanites and the Perizzites, the Hivites and the Jebusites, as the Lord your God has commanded….
Importantly, however, it should be noted that the Israelites received the express direction from God through none other than Moses to engage in the deliberate killing of others. In other words, as close to getting it straight from God’s mouth as you can get, besides directly from Jesus.
God does not need man to do His killing for Him. God rescued the Israelites from Egypt without one Israelite needing to kill one Egyptian. Ancient Egyptians died prompting the Exodus, but the Scripture records that the Lord ended their lives through miraculous means. God does not need conventional war to accomplish any of his aims. When Pharaoh changes his mind because slaves are difficult to economically replace, Pharaoh pursues the Israelites with military power to provoke them to return to Egypt. God solves this military problem with the Red Sea solution. Thus, God can fight human armies without His people shedding blood. So unless God actively speaks through a major prophet directing His people to engage in deliberate killing, there’s a lot of Scripture directing believers to not actively seek violent solutions to life’s issues.
Early church leaders directly spoke to the question of Christians and military service. I quote from Daniel H. Shubin’s, Militarist Christendom and the Gospel of the Prince of Peace:
The primary witness to the exclusion of early followers and disciples of the teachings of Jesus to military conscription is Tertullian…. He was the first great Latin apologists, writing 160-220 AD, having his center of ministry in northern Africa. The following passage is from Tertullian’s treatise On Idolatry: “…But how will a Christian man war, nay, how will he serve even in peace, without a sword, which the Lord has taken away? For albeit soldiers had come unto John, and received the formula of their rule; albeit likewise, a centurion believed; still the Lord afterward, in disarming Peter, disarmed every soldier. No uniform is lawful among us, if assigned to any unlawful action.”
According to Shubin, “Tertullian felt the allegiance given the state through the military oath to defend the nation against all enemies as defined by the Senate to be disloyal to the true God…. Tertullian also mentions that soldiers who become Christians while in the military resigned themselves from that vocation.” Likewise in the Ante-Nicene Fathers we find that Cyprian (c. 208-258 A.D.), a student of Tertullian, wrote in his Epistles:
The whole world is wet with mutual blood; and murder, which in the case of the individual is admitted to be a crime, is called virtue when it is committed wholesale.
Justin of Caesarea (c. 103-165 A.D.), also known as Justin Martyr, said in his First Apology (c. 140-160 A.D.):
And when the Spirit of prophesy speaks as predicting things that are to come to pass, He speaks in this way. “For out of Zion shall go forth the law, and the word of the Lord from Jerusalem. And He shall judge among the nations, and shall rebuke many people; and they shall beat their swords in to ploughshares, and their spears into pruning hooks; nations shall not lift up sword against nation, neither shall they learn war anymore.” And that it did so come to pass, we can convince you. For from Jerusalem there went out into the world, men, twelve in number, and these illiterate, of no ability in speaking; but by the power of God they proclaimed to every race of men that they were sent by Christ to teach to all the word of God; and we who formerly used to murder one another do not only now refrain from making war on our enemies, but also, that we may not lie nor deceive our examiners, willing die confessing Christ.
I could go on with other examples showing the early church frowned on Christians making war. Origen (c. 185-254 A.D.) probably said it best: “For we no longer take up sword against nation, nor do we learn war any more, having become children of peace, for the sake of Jesus who is our leader….”
Based on the foregoing most contemporary American evangelicals should be asking: “How come I’ve never been taught that God might have an opinion about military service?” I’ll address this question in my next blog on this topic.
 Genesis 4:2b-12 (NIV)
 Exodus 21:12-14 (NIV)
 Exodus 20:13 (NIV)
 See Deuteronomy 1:6-8 (NIV)
 Deuteronomy 20:16-17 (ESV)
 See Exodus 12:29-30 (NIV)
 I doubt we’ve experienced a major prophet in the post-biblical era.
 Shubin, pg. 38 where Shubin quotes Ante-Nicene Fathers, vol. 3, pg. 99-100.
 Shubin, pg. 40-41.
 Ante-Nicene Fathers, vol. 5, pg. 277.
 Id. at vol. 1, pg 175-176.
 Against Celsus, 5:33.