Alright, not talking much on the nature of sin itself but rather on capital punishment. Christians should know where they stand on this issue, because the bible is clear that God is for capital punishment, ironically most "Christians" are just as confused as everyone else.
Let me show you guys biblical teaching on capital punishment.
I've had plenty of time to find my scriptures and will have at it... Please, I'm not trying to start a huge debate but I really want to defend this position. I've spent

of time on this so please forgive me on the length.
First - Old Testament
Genesis 9:5-6
5 Surely for your lifeblood I will demand a reckoning; from the hand of every beast I will require it, and from the hand of man. From the hand of every man’s brother I will require the life of man.
6 “Whoever sheds man’s blood,
By man his blood shall be shed;
For in the image of God
He made man.
God spoke these words to Noah after the flood in context of the covenant He made with mankind to never again destroy mankind by flood. (Note: This command preceded the Mosaic Law which by nature was temporal until fulfilled by Christ in the New Covenant ) This covenant was not temporal, but eternal in nature... thus exist in the New Covenant
Man is made in the image of God; therefore, a fatal attack against God's image-bearers is an attack against God Himself. This is the reason God commanded that the individual who sheds another man's blood shall have his own blood shed as well.
When we come to the Mosaic Covenant we find an many crimes for which capital punishment was applicable. The Law of Moses instructed the penalty of death for many offenses, most of which were moral and religious in nature. While human government is no longer responsible for dealing out capital punishment for most moral and religious offences (as they were under Mosaic Law), they are still responsible for administering capital punishment in the case of the intentional murder of an innocent human being (Noahic Covenant).
You shall not kill. (Exodus 20:13; see also Deuteronomy 5:17)
The hebrew word for kill is ratsach which always refers to the murder of another human being (whether it be intentional or accidental). Although there are more words for kill that refer to the taking of life a accurate word for ratsach is "murder". Muwth is another word means to kill, often prematurely; i.e. execution. This is the power God has over His creation (Deuteronomy 32:39), what God intended to do to Moses for not circumcising his son, what God commanded Israel to do to those who sacrifice their children to Molech, and what David consented to be done to him had he been guilty of any wrongdoing against Saul (II Samuel 14:32). The prohibition in the Ten Commandment then, is against murder, not killing. It is a prohibition against the unjust taking of innocent human life, not the taking of any life whatsoever.
It's wise for use to to make a clear distinction between killing and murder as well. Killing can be just, but murder is always unjust. That's why it is factually incorrect to say capital punishment is the killing of those who kill others. Capital punishment is the killing of those who murder others. It would be equally wrong to say capital punishment is the murdering of those who murder others. Taking the life of an individual who unjustly took the life of another human being is not murder, but killing. To use "killing" or "murder" of both parties interchangeably is to confuse the just taking of life with the unjust.
New Testament
Pilate therefore said to Him, "You do not speak to me? Do You not know that I have authority to release You, and I have authority to crucify You?" Jesus answered, "You would have no authority over Me, unless it had been given you from above; for this reason he who delivered Me up to you has the greater sin." (John 19:10-11, NAS)
Alright, what is important to note about this passage is that Jesus did not challenge Pilate's governal right to sentence Him to death. He implicitly affirmed Pilate's right to administer capital punishment, and that the right came from God. He did not say, "You have no authority to do this," but rather - "You only have this authority because it is given to you by God." Pilate thought he held the power of Jesus' life in his own hand, but Jesus countered that Pilate would not be able to crucify Him unless God allowed him to do so.... Jesus challenged the source of Pilate's right, not the right itself.
There is no question that the state's execution of Jesus was unjust (because Jesus was innocent, and capital punishment is for the guilty), but that is no reflection on the just nature of capital punishment itself. While there may be unjust applications of a state's right to execute certain criminals for purposes of justice, it does not taint the just nature of capital punishment itself.
Now turn your attention to Paul -
Let every person be subject to the governing authorities. For there is no authority except by God's appointment, and the authorities that exist have been instituted by God. 13:2 So the person who resists such authority resists the ordinance of God, and those who resist will incur judgment 13:3 (for rulers cause no fear for good conduct but for bad). Do you desire not to fear authority? Do good and you will receive its commendation, 13:4 for it is God's servant for your good. But if you do wrong, be in fear, for it does not bear the sword in vain. It is God's servant to administer retribution on the wrongdoer. (Romans 13:1-4)
According to Paul the purpose of human government is to reward good and punish evil...
Festus, wanting to do the Jews a favor, asked Paul, "Are you willing to go up to Jerusalem and be tried before me there on these charges?" 25:10 Paul replied, "I am standing before Caesar's judgment seat, where I should be tried. I have done nothing wrong to the Jews, as you also know very well. 25:11 If then I am in the wrong and have done anything that deserves death, I am not trying to escape dying, but if not one of their charges against me is true, no one can hand me over to them. I appeal to Caesar!" 25:12 Then, after conferring with his council, Festus replied, "You have appealed to Caesar; to Caesar you will go!" (Acts 25:9-11)
Paul had been imprisoned for approximately two years when he stood trial before Festus. The Jews in attendance brought many accusations against him. Paul maintained his innocence from those charges, but did not object to being put to death if he had done anything that was deserving of death. Paul did not object to the possibility of capital punishment by arguing that it was unjust punishment... or in contradiction to God's design. To the contrary, he acknowledged there were crimes deserving of death, and was willing to submit to that penalty had he actually committed those crimes.
I believe this to be on topic and not directly dealing with the nature of sin but the justification of capital punishment from a "Christian" point of view.