As God's law is forgotten sexual impurity becomes pervasive in a society. Even God's people need to exercise constant vigilance to think and act chastely.

1. The Scope Of The Seventh Commandment - Exodus 20:14
We have often noted that the Ten Commandments were written using the literary device known as "synecdoche." Understanding this we realize that the seventh commandment covers all forms of sexual uncleanness. This would include:
a. Fornication - This is any form of illicit sexual intercourse and can include adultery.
b. Adultery - This is the sexual unfaithfulness of a married individual.
c. Divorce and remarriage upon unscriptural grounds (Matthew 19:9).
d. Sexual Perversion (Leviticus 18:22-25, Romans 1:24-28, I Corinthians 6:9).
e. Incest (Leviticus 18:1-19, I Corinthians 5:1, Mark 6:18).
f. Unclean Thoughts (Matthew 5:27-28).
g. Anything that leads to or encourages impurity.

We have already noted that the commandments each deal with a particular class of evil. Often the most serious form of evil in each category is mentioned. This being so one might wonder why the seventh commandment mentions adultery rather than some of the more shocking perversions.
This is understood when we remember that the purpose of the seventh commandment is to protect the family and the institution of marriage. God Himself created and authorized marriage for the well-being of human kind (Genesis 2:21-25). Not AIDS but the destruction of the family is the most dangerous effect of immorality.

2. The Casualties Of Sexual Uncleanness
a. Marriages - Adultery and all other forms of impurity are an assault on the home. Notice what divorce, illicit cohabitation, and now "same sex" marriages have done in America. Strong homes are now the exception in America since the so-called sexual revolution.
b. Children - How could God assure that every child would be welcomed into this world and provided a safe and loving environment? He instituted marriage and legalized sexual love only between husband and wife. In this way children would have a home with the nurture of both father and mother. To see the damage done to children by sexual promiscuity one only needs to look around. Divorce, illegitimacy, single parent homes, abuse and abortion are all the effects of our permissive lifestyles. Only can only weep to think of the misery that uncontrolled lust has brought on children.
c. Romantic Love - Permissiveness is not the aid but the enemy of true love. Permanent commitment becomes rare as society becomes loose. Studies have shown that couples that cohabit before marriage have a low success rate when and if they do marry.
d. Physical health - In every age disease has plagued societies where God's marriage laws were disobeyed (Proverbs 5:3-12).
e. God's Honor - Immorality brings disobedience and dishonor to God.
(1) It is rebellion against God the Father who gave the law.
(2) It is a misuse of the body which in Christians belongs to Christ (I Corinthians 6:15-18).
(3) It is among Christian people a defiling of the Temple Of God (I Corinthians 6:19-20).
f. Our Souls - All sin is damning apart from redemption through Christ. Those whose lives are characterized by unrestrained impurity give no evidence of a new birth (Hebrews 13:4, Proverbs 6:32, I Corinthians 6:9-10). True Christians can fall into sexual sin. Those truly saved will be brought to repentance. David’s psalm of repentance after his sin with Bathsheba is an example (Psalm 51).

3. Paths To Sexual Impurity - II Timothy 2:22, Romans 13:14
a. The Ten Commandments not only forbids sin but that which leads to it. Those who would avoid immorality must avoid the paths that lead there.
(1) Evil Thoughts - Matthew 5:28
(2) Unchaste Looks - Matthew 5:28
b. Failure to avoid compromising or tempting situations. Temptations must not be trifled with. Joseph gives us a wonderful example of how to flee temptation (Genesis 39:7-12).
(1) Careless Flirtation - Much adultery comes about as men and women allow flirtations to grow into infatuations. In our day where the sexes are mixed in the workplace this is a real problem. Our hearts must be guarded (Proverbs 4:23) and our minds fixed on our spouse (Proverbs 5:18).
(2) Immoral Literature and Entertainment (Philippians 4:8).
(3) Immodest Dress (I Timothy 2:8-10, Proverbs 7:10) - There is no excuse for sexually provocative dress. Women are responsible for their influence. We are all our "brother's keeper."
(4) Poor Marriages - Marriages are intended to be loving and mutually gratifying relationships (I Corinthians 7:1-3, Proverbs 5:15 & 18).
(5) Evil Companions - II Samuel 13:1-15
(6) Intoxication - Proverbs 23:29-33, Habakkak 2:15

4. The Value Of The Law
a. Contrary to the view of fools this law is the great protector of family and human happiness.
b. This law like all others reveal our need of Christ. Who can plead innocence in God's sight (Romans 3:20). The penalty is Hell but believers find forgiveness through Jesus Christ (John 8:1-11).