In Bible translations and Bible commentaries and so on, when they talk about premarital sex they often refer to it as "fornication."
Is fornication a sin?
Fornication is a sin against our own body, and we are told to run away from fornication:
"Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body. What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's." (1 Corinthians 6:18-20, KJV)
The Israelites committed fornication in the wilderness, and thousands of them were killed. This was written down as an admonishment (warning) to us:
"Neither let us commit fornication, as some of them committed, and fell in one day three and twenty thousand. Neither let us tempt Christ, as some of them also tempted, and were destroyed of serpents. Neither murmur ye, as some of them also murmured, and were destroyed of the destroyer. Now all these things happened unto them for ensamples: and they are written for our admonition, upon whom the ends of the world are come." (1 Corinthians 10:8-11, KJV)
Paul gave the Galatian church a list of sins of the flesh, and notice that adultery and fornication were at the top of the list:
"Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness, Idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, Envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God." (Galatians 5:19-21, KJV)
