“Lament and mourn and weep! Let your laughter be turned to mourning and your joy to gloom.”
The 7th command is “morn.” “Mourn” means to be sad, grieve. The idea is to suffer sadness or grief as the result of depressing circumstances. “Mourning” implies deep contrition, deep remorse. The idea is that we feel towards someone who falls into sin like we feel when someone close to us dies.
Mt 5:4 “Blessed are those who mourn,
For they shall be comforted.”
2 Co 12:21 “Lest, when I come again, my God will humble me among you, and I shall mourn for many who have sinned before and have not repented of the uncleanness, fornication, and lewdness which they have practiced.”
Sensitiveness to sin is important to a healthy spiritual life.
Genuine repentance involves grief over sin; it does not take sin lightly. There is a tendency for us to cushion our personal sin, to rationalize it.
2 Co. 7:9-12 “Now I rejoice, not that you were made sorry, but that your sorrow led to repentance. For you were made sorry in a godly manner, that you might suffer loss from us in nothing. 10 For godly sorrow produces repentance leading to salvation [salvation from a ruined Christian life], not to be regretted; but the sorrow of the world produces death. 11 For observe this very thing, that you sorrowed in a godly manner: What diligence it produced in you, what clearing of yourselves, what indignation, what fear, what vehement desire, what zeal, what vindication! In all things you proved yourselves to be clear in this matter. 12 Therefore, although I wrote to you, I did not do it for the sake of him who had done the wrong, nor for the sake of him who suffered wrong, but that our care for you in the sight of God might appear to you.”
There are times when it is necessary to impose upon self a sorrow over our sin.
Ro 7:24-25 “O wretched man that I am! Who will deliver me from this body of death? 25 I thank God—through Jesus Christ our Lord! So then, with the mind I myself serve the law of God, but with the flesh the law of sin.”