The study uses a systematic method of word study to define the word "fornication" by only comparing the Scriptures by the Scriptures. In this method, we start with a clear New Testament teaching, find the Greek word, then find a verse that will send us back to the Old Testament, for which we can then do a systematic study of the Old Testament.
Here we start at Hebrews 13:4 and from our concordance find that the Greek word for whoremongers/fornicators is "pornos" (Strong's 4205). By looking up the word "pornos" we can find that there are three Greek words that are very similar: "porne" (Strong's 4204) which is translated as "harlot" or "whore" and "porneuo" which is translated as "commit fornication". Of all these, we desire to find a verse that will send us back to Old Testament Hebrew. In Hebrews, we can find a verse that relates back to the Old Testament:
This verse refers back to the book of Joshua in the Old Testament. Specifically Joshua 6:17 says:
From this verse, we can find that the Hebrew word for "harlot" is "zanah".
Now we look specifically for the word "zanah" for Scriptures that have some sort of context.
We find that the first place it is used is in Genesis 34:31. However for context, we will list Genesis 34:1-9:
And Dinah the daughter of Leah, which she bare unto Jacob, went out to see the daughters of the land. And when Shechem the son of Hamor the Hivite, prince of the country, saw her, he took her, and lay with her, and defiled her. And his soul clave unto Dinah the daughter of Jacob, and he loved the damsel, and spake kindly unto the damsel. And Shechem spake unto his father Hamor, saying, Get me this damsel to wife.
Then in verse 31, it is written:
The Hebrew word "zanah" is also translated in Genesis 38:15 as harlot:
Here a whore is also one who prostitutes or sells herself for hire.
Ezekiel 16 is filled with different variations of the word harlot, whore, and fornication. And thus gives a good context for what a harlot is: a beautiful woman that rose up and went after everyone she could.
v4. ...in the day thou wast born thy navel was not cut, neither wast thou washed in water to supple thee...
v5. ...None eye pitied thee, to do any these unto thee, to have compassion upon thee; but thou was cast in the open field...
v6. And when I passed by thee, and saw thee polluted in thine own blood, I said unto thee... Live; yea, I said unto thee when thou wast in thy blood, Live.
v7. I have caused thee to multiply as the bud of the field, and thou hast increased and waxen great, and thou art come to excellent ornaments: thy breasts are fashioned, and thine hair is grown, whereas thou wast naked and bare.
v8. ...I spread my skirt over thee, and entered into a covenant with thee, saith the LORD GOD, and thou becamest mine.
v9. Then washed I thee...
v10. I clothed thee... and shod thee...
v11. I decked thee also with ornaments, and I put bracelets upon thy hands...
v12. I put a jewel on thy forehead, and earrings in thine ears...
v13. ...thou wast exceeding beautiful, and thou didst prosper into a kingdom.
v15. But thou didst trust in thine own beauty, and playedst the harlot because of thy renown, and pourest out thy fornications on every one that passed by; his it was.
v16. And thy garments thou didst take, and deckedst thy high places with divers colors, and playedst the harlot thereupon...
v17. Thou hast also taken thy fair jewels of my gold and of my silver, which I had given thee, and madest to thyself images of men, and didst commit whoredom with them...
v18. ...thou hast set mine oil and mine incense before them
v19. ...I fed thee, thou hast even set it before them for a sweet savour
v20. Moreover thou hast taken thy sons and thy daughters, whom thou hasat borne unto me, and these hast thou sacrificed unto them to be devoured. Is this of thy whoredoms a small matter...?
v22. And in all thine abominations and thy whoredoms thou hast not remembered the days of thy youth, when thou wast naked and bare, and wast polluted in thy blood.
v25. ...multiplied thy whoredoms...
v26. Thou hast also committed fornication with the Egyptians thy neighbors, great of flesh; and hast increased they whoredoms to provoke me to anger.
v28. Thou hast played the whore also with the Assyrians, because thou wast unsatiable; yea, thou hast played the harlot with them, and couldest not be satisfied.
v29. Thou hast moreover multiplied thy fornication in the land of Canaan unto Chalde'a; and yet thou wast not satisfied herewith.
v30. How weak is thine heart, saith the Lord GOD, seeing thou does all these things,the work of an imperous whorish woman;
v31. ...makest thine high place in every street; and hast not been as a harlot, in that thou scornest hire;
v32. but as a wife that committeth adultery, which taketh strangers instead of her husband!
v33. They give gifts to all whores:
Ezekiel 16
Once we have studied by the Scriptures alone what "fornication" means, then it is helpful to compare with the conclusions to which others have come. For example, BlueLetterBible.org gives the following definition:
Fornication comes from the Greek word porneia (4202) and means (1):
1) illicit sexual intercourse
1a) adultery, fornication, homosexuality, lesbianism, intercourse with animals, etc.
1b) sexual intercourse with close relatives; Leviticus 18
1c) sexual intercourse with a divorced man or woman; Mark 10:11,12
2) metaph. the worship of idols
2a) of the defilement of idolatry, as incurred by eating the sacrifices offered to idols
There are 26 instances of the word porneia in Mat 5:32, 5:19, 19:9, Mat 7:21, John 8:41, Acts 15:20, 15:29, 21:25, Romans 1:29, 1Cor 5:1, 6:13, 6:18, 7:2, 12:21, Gal 5:19, Eph 5:3, Col 3:5, 1Th 4:3, Rev 2:21, 9:21, 14:8, 17:2, 17:4, 18:3, 19:2.
Fornication is the wreckless setting aside of what God has clearly stated, entering into a relationship which was designed only under a marriage covenant.