Adultery

There are two types of adultery spoken of in the Bible:

1. SEXUAL ADULTERY—"Conjugal infidelity. An adulterer was a man who had sexual intercourse with a woman he was not married to, either a married woman or one who was engaged to be married. A woman who did the same thing was an adulteress. Adultery is fornication. The Bible regards adultery as a great sin and a great social wrong. It has been inferred from John 8:1-11 that this sin became very common during the age preceding the destruction of Jerusalem."
Author: Matthew G. Easton.

Adultery without sexual intercourse—Jesus Christ warned, "You have heard that it was said to those of old, 'You shall not commit adultery.' But I say to you that whoever looks at a woman to lust after her has committed adultery already with her in his heart." As with the breaking of any of the Ten Commandments, those who are not washed in the blood of Jesus Christ will have to pay the penalty. They will not enter the Kingdom of God. Punishment for transgression of this Commandment is the death penalty.
Author: Ray Comfort.

2. SPIRITUAL ADULTERY—Idolatry, covetousness, and apostasy are spoken of as spiritual adultery (Jer. 3:6,8,9; Ezek. 16:32; Hos. 1:2:3; Rev. 2:22). An apostate church is an adulteress (Isa. 1:21; Ezek. 23:4,7, 37), and the Jews are described "an adulterous generation" (Matt. 12:39) (compare Rev. 12.)
(the above is from: http://www.christiananswers.net/dictionary/adultery.html)

Lust Part 1


Lust Part 2


Lust Part 3



Fornication

Hebrew: zanah / Greek: porneia

Fornication is voluntary sexual intercourse between a man and woman who are not married to each other. Adultery is one type of fornication.

In every form, fornication was sternly condemned by the Mosaic law among God's people, the Israelites (Lev. 21:9; 19:29; Deut. 22:20-11, 23-29; 23:18; Ex. 22:16). (See ADULTERY.)

Fornication is also mentioned many times in the New Testament (Matt. 5:32; 19:9; John 8:41; Acts 15:20, 29; 21:25; Rom. 1:29; 1 Cor 5:1, 6:13, 18, 7:2; 10:8; 2 Cor 12:21; Gal 5:19; Eph 5:3; Col 3:5; 1 Thess. 4:3; Jude 1:7; Rev. 2:14, 20-21; 9:21; 14:8; 17:2,4).

"The Greek word for 'fornication' (porneia) could include any sexual sin committed after the betrothal contract. …In Biblical usage, 'fornication' can mean any sexual congress outside monogamous marriage. It thus includes not only premarital sex, but also adultery, homosexual acts, incest, remarriage after un-Biblical divorce, and sexual acts with animals, all of which are explicitly forbidden in the law as given through Moses (Leviticus 20:10-21). Christ expanded the prohibition against adultery to include even sexual lusting (Matthew 5:28)." (Dr. Henry M. Morris)

The word "fornication" is sometimes used in a symbolic sense in the Bible, for example, meaning a forsaking of God or a following after idols (Isa. 1:2; Jer. 2:20; Ezek. 16; Hos. 1:2; 2:1-5; Jer. 3:8-9).
(the above is from: http://www.christiananswers.net/dictionary/fornication.html)