Marriage to an Adulterer or an Adulteress is Invalid

Question :

What is the meaning of the Noble Verse:
"The adulterer-fornicator marries not but an adulteress-fornica-tress or a Mushrikah; and the adulteress-fornicatress, none marries her except an adulterer-fornicator or a Mushrik [and that means that the man who agrees to marry (have a sexual relation with) a Mushrikah (female polytheist, pagan or idolatress) or a prostitute, then surely, he is either an adulterer-fornicator or a Mushrik (polytheist, pagan or idolater). And the woman who agrees to marry (have a sexual relation with) a Mushrik (polytheist, pagan or idolater) or an adulterer-fornicator, then she is either a prostitute or a Mushrikah (female polytheist, pagan, or idolatress)]. Such a thing is forbidden to the believers (of Islamic Monotheism).
And does a person's faith change to Shirk by committing this sin?

Answer:

If we read this Noble Verse, which Allah has ended with His Words:
"Such a thing is forbidden to the believers "

We derive a ruling from it. That is the forbiddance of marrying an adulteress, or an adulterer. Meaning that it is not permissible for a man to marry an adulteress, and it is not permissible for a man to marry an adulterer to his daughter. If we know this:
"Such a thing is forbidden to the believers."

then whoever committed this sin does not fall outside of two possible situations:
Either he accepts its prohibition and believes in it, but he marries due to passion or desire. In this case he will be an adulterer, because he has made a forbidden contract, which he believes is forbidden and which he accepts is forbidden. It is well known that a forbidden contract does not make the private parts permissible, nor enjoyment of them. Therefore by making permissible the private parts of the woman whom he married - who is an adulteress when he knows and accepts that this is forbidden, the action of this man will be considered adultery.

The other case is when he does not accept this ruling and he says: "This is absolutely not forbidden; rather, it is permissible." In this case, he will be a Mushrik. Because whoever declares permissible that which Allah has forbidden, then he has made himself a lawmaker beside Allah, thus associating partners with Him, Most Glorified, Most High. This is why He, Most Glorified, Most High says:
"Or have they partners (with Allah false gods) who have instituted for them a religion which Allah has not ordained?"

Allah has declared that those who legislate for Allah's creatures, in religion with what He has not permitted any partners in like the one who legislates for himself the lawfulness of marrying an adulteress and does not accept the legal ruling-that he will be a Mushrik.

In short, the one who marries an adulteress either believes and accepts that it is forbidden, in which case he will be an adulterer, or he does not believe that it is forbidden, nor does he accept it. Rather, he denies that it is forbidden, in which case, he will be a Mushrik, because he has declared permissible that which Allah has forbidden, which is why Allah, the Almighty, the All-Powerful says:

"And the woman who agrees to marry (have a sexual relation with) a Mushrik (polytheist, pagan or idolater) or an adulterer- fornicator, then she is either a prostitute or a Mushrikah (female polytheist, pagan, or idolatress)."

He is an adulterer if he accepts and believes that it is forbidden, or he is a Mushrik if he does not believe or accept that it is forbidden. And we say the same regarding one who gives his daughter in marriage to an adulterous man. But this ruling is withdrawn by repentance. So if the adulterer repents of his adultery and the adulteress repents of her adultery, this description is withdrawn from them. That is, the characterization of being an adulterer, just as the characterization of sinfulness is withdrawn from a sinner if he turns in repentance to Allah, the Almighty, the All-Powerful and abandons sin.

So if an adulterer repents of his adultery, or the adulteress repents of her adultery, it is permissible to marry them.