In the Scriptures, killing is not always a violation of the 6th commandment. It really depends on two things:
a) who has a right to kill, and
b) what are the seen and foreseen circumstances or events that brought about this death.
First off, regarding who has a right to kill? Only God, whom He allows or appoints, and who He so commands has a right to end someone’s life. However, for the most part, He reserves that right only to Himself. Why? What gives Him this right? Because He is the creator and giver of “bios” life (temporal life) and without Him there is no life, therefore, only He has the ultimate right or authority to take that life and do with it as He pleases just as you have right over a project or object you have made. But as we have seen in the above mentioned passage from Ezekiel, it actually grieves Him when this must take place.
But wait…don’t we create things also. Sort of, but when we create something, we use materials He has already created and secondly it is not alive. But do we still not have the right to destroy it if it is dysfunctional or not to our liking and then to make something else of the materials? Of course we do! I made a wooden cup once, but eventually it swelled, and warped, and no longer could serve its’ purpose. Then one day it split and began to leak, so I threw it into the yard for the kids to play with, and eventually it was destroyed, but that was my choice was it not? I understand that this is not a living thing, but the idea of one creating something, and having absolute control of its destiny is the point being made here. That is why God says, “Vengeance is mine, I will repay!” Only then is vengeance truly justified, for the Lord does not judge by outward appearances but knows the thoughts of the heart and the outcomes of all future actions.
Secondarily, when God says, you shall not kill, that does not mean in an absolute sense, as you will see, for we must first understand what He is saying here, and in order to do that, we must discern what He means here by the word “kill” in the commandment as opposed to what is meant in other places the translators also called “kill”! There are three different words used for killing in the Old Testament. So in order to uncover the circumstances or events under which killing is sometimes allowed, one must take into account the context of the act and which word is being used.
The Hebrew word “rasah” or “rashah”, as it is used here in the 6th Commandment refers most specifically to premeditated murder without just cause. However, it can also be used in the sense of manslaughter, as when one kills by mistake, or without intent, like in the case of Numbers 25:11; Deuteronomy 4:42, 19:4, Joshua 20:3-5, and elsewhere! Thus in Hebrew the specific meaning of this word must always be determined by its’ context. We must always see it in relation to the surrounding statements. In the commandments it is absolute and the law is conditional…
Sin is a transgression of the Law (1 John 3:4) and there are actually 613 commandments…the soul that sins it must die is called the curse of the law but actually goes all the way back to the garden and what is really being said is that sin brings forth sickness and death (spiritual death).
Next, we have the word “hemit”, which carries no sense of guilt or iniquity and is used in the case of righteous capital punishment, or when the killing is the result of an attack from a wild beast, and so on! The root of this word is related to the word “emet” or truth. We see this usage in Leviticus 20:4; Numbers 35:19-21; Deuteronomy 13:10 (your passage) and Deuteronomy 17:7!
Finally, when God orders the execution or destruction of an individual or group (like when He commands Joshua at the five cities of Canaan), the word “haraq” is used (See Genesis 20:4; Exodus 4:23, etc.). This form of killing is used specifically in the prevention of foreseen evils beyond our comprehension. By eliminating these people, God is actually sparing millions of people the pain, disease, suffering, and death that they would have caused. It would be used for example in eliminating an Adolph Hitler. There is absolutely nothing evil in this, in fact it is very good. Therefore, this form of killing is always just, whether or not we finite humans can see the full implications of His doing it.
The question has also been asked, “Why couldn’t God just make the devils repent and then save them rather than condemn them all to eternal death in Gehenna? I mean, didn’t Jesus die for all sins? Can’t He save them as well?”
And the answer is, yes, He could, but He won’t, because these are free-will beings who not only have made this choice, but God has foreseen that, even if given many opportunities, they still will not repent.
Therefore, regarding this type of death that they will suffer (eternal separation from the presence of God), and believing they know what this means, they still choose faithless rebellion, and so God is entirely justified, and no person who truly understands this can feel sorry for the malevolent beings of this universe who are being so judged. American mass murder (though he never actually did the killing) is such a person. He knows God is real and hates God, rejects God and mocks God. Clearly there are many other human spirits like this! In the end actual hell is merely the place God has provided where He is not and is in fact is giving them their way. They will be their own lord (Genesis 3:5) forever without God or anything He would have provided (light, fellowship, cooling breezes, order, touch, etc.)
Now then, according to the Scriptures a murderer is almost always a person who sits and premeditates the killing of another human being for some ultimate selfish reason such as hatred, jealousy, political power, revenge, profit, control, etc.! Originally mankind was made in God’s image, so when we take a life and shed another’s blood, we offend God. We are also killing all that persons potential future offspring. Mankind was also meant to be a progenitor of others and so when we murder, we eliminate the life of all those who were meant to have a life because of us who are not yet born. Did you know in Genesis the Lord tells Cain, your brother’s bloods call out from the ground and not your brothers blood? Yes in Hebrew the word is a plural.
God takes humanity’s mutual preservation of each individual’s life very seriously. So seriously in fact, as well as being aware of the human’s natural tendency for revenge and errors in judgment, we see that in the time of the Covenant of the Law with Israel, He also set up places of refuge (entire cities), and commanded each case be judged with fair trials obtaining witnesses (two or more that must be in agreement), but gave them a law the stemmed from the time of Noah which said, “If a man sheds the blood of another, by man his blood shall be shed”, and then finally recommends forgiveness for most sin and provides a system of blood sacrifice for sin, culminating when He gave His only begotten Son (Isaiah 53/John 3). The provision of animal sacrifice was of course only temporary looking forward to this “once for all” sacrifice of His Son (Hebrews 10:10), as an atonement that satisfies the requirement of life for life (Genesis 9:6/Isaiah 53). For without the shedding of blood there is no remission of sin. Therefore, this intent of God to treat each individual life as sacred is so serious that, as eluded to above, that Jesus the Messiah says that even anger and insult are violations of the 6th Commandment.
So why did our Lord do all this for us? Because of the potential danger that lurks within each of us when we act out as our own lord (Genesis 3:5) which is the true fruit of the tree of the knowledge of good and evil, by which we decide to disregard God’s word and decide good and evil for ourselves (do what is right in our own eyes...see the book of Kings). Sad as it seems to admit it, the source of these heinous and dangerous motivations is a genuine potential that lies within each of us (Matthew 15:19)! Who can deny it? Only the self-deluded!