Q: What is required in the seventh commandment?
A: The seventh commandment requires the preservation of our own and our neighbor's chastity, in heart, in speech and behavior.
1 Thessalonians 4:3-5 For this is the will of God, your sanctification: that you abstain from sexual immorality; that each one of you know how to control his own body in holiness and honor, not in the passion of lust like the Gentiles who do not know God.
Chastity is not a word we use very much today. In fact, the word probably has a lot of negative stereotypes attached to it. It may conjure up medieval images of maidens locked in towers by their fathers to keep them "pure", or perhaps stereotypes of Puritanical societies (based mostly upon Nathaniel Hawthorne's intentionally inaccurate depictions) where even discussing the subject of "sex" was considered impure and taboo. But the idea of chastity is not an idea that we as the people of God should shy away from. All of us, whether we are married, whether we are single, whether we are male or female, are called to be chaste. That is to say, we have a call to remain sexually pure, not only in our actions, but also in our hearts, thoughts, and speech. And not only are we to preserve our own chastity, we are to strive to preserve our neighbor's chastity as well.
Sexual purity, again not merely the outward actions but also the inward thoughts and conditions of our hearts, is about preserving God's pattern for sexuality. God designed sexual acts to be part of the marriage covenant. He designed the physical, emotional, and spiritual bond of sex to point to and reflect the reality of God's covenant with his people. It reflects the reality that God is our God, and we are his people forever, and this covenant is an intimate, pure, and close relationship! The God of all creation draws intimately close to his people, and this is a "closed relationship". We have no other God, and he has no other people. When we take sex out of the boundaries that God himself has put on it, we pervert God's good gift and we pervert his design for this gift.
This is why we are to pursue, to protect, to desire sexual purity in all aspects of our lives, and to preserve as far as we can the sexual purity of our neighbors. In doing so, we declare the goodness of God's gift and we declare the goodness of God's everlasting covenant between him and his people. We honor God and his design for his creation when we strive to live chaste lives.