What is the ruling on marrying a young man who committed a major sin and then repented, and must the wife distance herself from her husband if she learns of his commission of this major sin, and what is meant by His saying, the Almighty: "And that was forbidden to the believers"?

It is important for the suitor to adhere to religious principles and good morals. One whose outward appearance is righteous should not be questioned about his past, and he should conceal his own misdeeds. If he made a mistake, admitted it, and his repentance is confirmed, then marriage to him is permissible, because sincere repentance obliterates what came before it, and "the one who repents from sin is like one who has no sin." If the wife knows that her husband commits immoral acts, she should advise him and supplicate for him. If he responds, then all is well. Otherwise, it is permissible for her to seek divorce (talaq) or khul', but it is not forbidden for her to remain with him. As for the Almighty’s saying: "and that was forbidden to the believers," there are several interpretations: it refers to the prohibition of adultery, or marrying a polytheistic adulteress, or women who openly engage in prostitution.