This is the twenty-third post on Christian ethics in my ongoing series, theology in bullet points. The first unit in this series had to do with God and Creation (book here), and the second unit was on Christology and Atonement.
We are now in the third and final unit: The Holy Spirit and the Church. The first set of posts in this final unit was on the Holy Spirit. The second set was on the Church. The third set was on sacraments. This final section is on Christian ethics.
Thou shalt not covet.
1. The final commandment has a different character than all but perhaps the first commandment. Almost all the other commands directly address actions: making an idol, taking an oath falsely, violating the sabbath, dishonoring one's parents, killing, committing adultery, stealing, lying under oath.
By contrast, the tenth commandment addresses one's attitude and disposition toward other people. Do not stew or scheme in relation to your neighbor's property. Do not fantasize or plot in relation to his wife or his servants. The ancients were not introspective in the extreme way of post-Romantic Western culture. The tenth commandment was not about passing thoughts. It was about a disposition that, given the right circumstances, would lead to a violation of the other commandments.
2. There is of course a very strong similarity between what the tenth commandment does to the other commandments and Jesus' teaching in the Sermon on the Mount. In Matthew 5, Jesus as it were addresses a view of the commandments that does not take the command not to covet into account.
It is not enough not to go through with a murder, he says in Matthew 5:21-26. You cannot covet the death of your neighbor or enemy. You cannot hate your neighbor such that, given the opportunity, you would do him or her harm.
It is not enough just not to go through with adultery, he says in Matthew 5:27-30. You cannot covet someone else's spouse. You cannot lust and fantasize after someone married to someone else such that, given the opportunity, you would have an affair with them.
Jesus extends this dynamic to the point of divorce. Coveting someone else's spouse can lead you to divorce your own spouse so that you can legally have sex with someone else. But this is simply legalized covetousness.
3. This movement toward the internalization of ethics is key to the New Testament and Christian ethics. Even among secular ethicists, it is recognized that one's motives and one's attitudes are the heart of morality. What we do is important, but our motivations for what we do are far more morally significant. Love of God and neighbor is the fundamental principle of Christian ethics.
It is also interesting that when Paul wished to show that it is impossible to keep the Law without the Holy Spirit, he chose to focus on the commandment not to covet (Rom. 7:7-8).  With regard to most of the other commandments, someone might say, "I have perfectly kept that command." I have never murdered anyone. I have never stolen from anyone. I have never slept with someone else's wife. I have never lied as a witness in court.
But Paul uses the command not to covet as his benchmark, a command that effectively internalizes the standard. I may be able not to murder someone but it will be very difficult without the Holy Spirit to love my enemy. I may be able not to have an affair but I need the help of the Holy Spirit to help me not to lust after other women.
The command not to covet is thus a crucial link between the Old and New Testament. It takes the other commandments out of the realm of the external and moves it into the realm of the heart.
Next Sunday: ET24: We must work out our salvation with fear and trembling.
 A fact pointed out by E. P. Sanders in Paul (1991).