Is it permissible to supplicate for the guidance of a non-Muslim, and then for marriage to him after his conversion to Islam, knowing that he commits grave sins such as homosexuality, consuming alcohol, and fornication? And does Islam [truly] obliterate what came before it in these cases?

A sensible Muslim woman should weigh matters according to the scales of Sharia and intellect, not emotion, especially in marriage, which is a prolonged life and a family. She must not succumb to the whispers of Satan. Allah has commanded believing men and women to lower their gaze, for it is a purification for them and a mercy upon them, as the eye is the messenger of the heart. It is permissible to pray for a disbeliever's guidance with the intention of pleasing Allah and saving him from torment, not with the intention of marriage, because becoming attached to a disbeliever in the hope of his conversion is irrational. Therefore, one must divert thoughts from this person, especially given his grave sins and immoral character, as this only increases the heart's attachment to him.