QUESTION
What does the Bible say about Premarital sex? What did Jesus say?

ANSWER
Jesus speaks of a list of humankind habits of life in which sexual immorality is mentioned. The term “sexual immorality” is the word fornication and means “sexual intercourse” outside of the marriage relationship. Jesus’ list can be seen in the Gospel of Mark at 7.20-23.

In the New Testament book of Galatians written by Paul, he writes a list of human habits of life which are not pleasing to God. They are called the “works of the flesh.” (Gal. 5.19-21) The first three “works” and the last one comment on sexuality.

SEXUAL SINS
Sexual immorality: Sexual intercourse outside of the marriage relationship (Illustration: 1 Cor. 5.1ff). Intercourse outside of marriage breaks down the stability of a family. The word “adultery” found in the KJV does not appear in reliable manuscripts.

Impurity: The general word for immoral activity that shuts a person off from God’s presence. The opposite lifestyle is found at Matthew 5.8 where Jesus says that God will bless those who have a pure heart. One could translate “pure in heart” as “with no ulterior motives. Those empowered people will have continued fellowship with God. It is fair to say that our motives should be adjusted to God’s motives. This is a change of Story, for the story we live in to God’s Story.

Debauchery: This means lack of restraint. A love for sin so reckless that the one sinning has ceased to care what God or man thinks of his actions. No attempt is made to hide the sin; it is committed in the open (1 Pet. 4.3; Jude 4). Debauchery shocks public civility. It does not care what God or people think.

Orgies: Sexual orgies were characteristic of pagan worship.

I trust this answer will help in your ongoing discovery process.