As a single person, if I have sex with someone, am I married to that person according to the Bible?

This website is what troubles me and leads me to believe I am bound by my sexual sins to being married. Paul said the harlot is one flesh with her john. According to some, this is marriage. I am deeply troubled by this and want an answer, yet there doesn’t seem to be one. I have sinned sexually in the past and have since met a woman I would like to pursue a marriage with. Have I ruined my chance at this?

That “oneness” is a physical oneness.  As 1 Corinthians 6:18 says “…joined to an harlot is one body.”  Verse 18 calls it a sin “against his own body.” 

The whole context is reasoning that our bodies are for serving God, not for “fornication.”  Therefore being joined to a harlot is not marriage, but fornication.  If it was marriage then it would not be a sin.

Now most of all, you need to learn the truth of the gospel.  We who have believed that the Lord Jesus died for our sins and was raised for our justification (I Corinthians 15:3,4 & Romans 4:25), we know we are dead to sin (Romans 6:2).  This is also the greater context of I Corinthians 6:9-12  “Know ye not that …fornicators … And such were some of you: but ye are washed, but ye are sanctified, but ye are justified in the name of the Lord Jesus, and by the Spirit of our God.”

You are focused on your flesh and your sins and not on the fact that our Savior dealt with our sins, and before God we are “not in the flesh” (Romans 8:9).

If you know and believe these things it does not matter what you have done in the past, or what a website says.  It matters what God says.  Don’t let any man (even yourself) put you under a yoke of bondage but “Stand fast therefore in the liberty wherewith Christ hath made us free.”