Sex is literally the joining of two spirits to become one flesh. Hence why a married women can not go on to be with another man unless her husband dies. Because her soul has become tied to him through sex hence marriage
let’s look at this precept for example
1 Corinthians 6:15-16
Our bodies are the members of Christ, and temples of the Holy Ghost: they must not therefore be defiled
15 Know ye not that your bodies are the members of Christ? shall I then take the members of Christ, and make them the members of an harlot? God forbid.
16 What? know ye not that he which is joined to an harlot is one body? for two, saith he, shall be one flesh.
where else does it refer to this in the bible?
back in genesis when first speaking of marriage..
Ephesians 5:28-31
28 So ought men to love their wives as their own bodies. He that loveth his wife loveth himself.
29 For no man ever yet hated his own flesh; but nourisheth and cherisheth it, even as the Lord the church:
30 For we are members of his body, of his flesh, and of his bones.
31 For this cause shall a man leave his father and mother, and shall be joined unto his wife, and they two shall be one flesh.
now, to understand some things, biblically virgin can mean two things, it doesn’t just have to mean = untouched sexually, it can also translate to UNMARRIED. a lot of references to unmarried women biblically = virgin. hence why Mary was called a virgin. most times you will find unmarried women being refereed to as such, as well. it’s kinda interchangeable as it’s the same thing since once a women is married through either the joining of spirits or through the ceremony she no longer is one and has a husband.
Leviticus 21:13-14
Of his marriage
13 And he shall take a wife in her virginity.
14 A widow, or a divorced woman, or profane, or an harlot, these shall he not take: but he shall take a virgin of his own people to wife
these precepts are crucial to understanding why adultery is looked down upon because by dishonoring your wife or husband through such acts you are also sinning against yourself since two have become ONE flesh.