In the first place, we would like to stress that having sex outside marriage is totally forbidden in Islam. Thus, one must repent to Allah and seek His Forgiveness for all that has been done. In fact, Islam prohibits all ways leading to fornication, adultery, and all forms of sexual perversion. In a practical and matchless approach to prevent the crime of Zina before its occurrence, Islam blocks all ways leading to that which is Haram and unlawful. Stressing this, Allah Almighty says, “And come not near unto adultery. Lo! it is an abomination and an evil way.” (Al-Israa’: 32)
However, if a man and woman committed Zina, they have to sincerely repent to Allah and seek His forgiveness. If they repent and wish to get married, they can do so. They should fear Allah, change their lifestyle, and spare no efforts to attain Allah’s forgiveness.
Dr. Muzammil H. Siddiqi, President of the Fiqh Council of North America, states: “These problems come when people do not follow the limits set by Allah. The Prophet (peace and blessings be upon him) said, “He who goes around the boundary line may cross it.” Muslims have to keep in mind that engagement (khitbah) does not make it halal for the couple to get intimate relations. They should not meet each other alone.
I suggest that both man and woman involved in this act ought to repent sincerely and ask Allah to forgive you. You must promise to Allah that you will try your best to abide by His rules and will not commit haram. After the sincere repentance, if you want to marry each other and live a pious and good life, you may do so. This should be done only after sincere repentance and prayers.”