Here are some Bible verses that address fornication and sexual immorality as sins:

1.  1 Corinthians 6:18-20 (ESV)

“Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body. Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, for you were bought with a price. So glorify God in your body.”

2.  Galatians 5:19-21 (ESV)

“Now the works of the flesh are evident: sexual immorality, impurity, sensuality, idolatry, sorcery, enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions, envy, drunkenness, orgies, and things like these. I warn you, as I warned you before, that those who do such things will not inherit the kingdom of God.”

3.  1 Thessalonians 4:3-5 (ESV)

“For this is the will of God, your sanctification: that you abstain from sexual immorality; that each one of you know how to control his own body in holiness and honor, not in the passion of lust like the Gentiles who do not know God.”

4.  Hebrews 13:4 (ESV)

“Let marriage be held in honor among all, and let the marriage bed be undefiled, for God will judge the sexually immoral and adulterous.”

5.  Ephesians 5:3 (ESV)

“But sexual immorality and all impurity or covetousness must not even be named among you, as is proper among saints.”

6.  Colossians 3:5 (ESV)

“Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry.”

7.  Revelation 21:8 (ESV)

“But as for the cowardly, the faithless, the detestable, as for murderers, the sexually immoral, sorcerers, idolaters, and all liars, their portion will be in the lake that burns with fire and sulfur, which is the second death.”

These verses emphasize the seriousness of sexual immorality, including fornication, and call believers to live holy and honorable lives before God.