Does a conversation that took place between a young man and a young woman via Facebook, which included an offer and acceptance of marriage, their calling each other "my husband" and "my wife," and the knowledge of friends and acquaintances thereof, constitute a legally valid marriage contract (nikah sahīh shar'an) or a void marriage (nikah fāsid)? And does a divorce resulting from it take effect?

What happened between the questioner and the girl is not a legal marriage due to the absence of marriage conditions, such as offer and acceptance between the guardian and the husband, and the testimony of witnesses. A mere proposal of marriage and the girl's consent do not constitute a legal contract. He must sever the relationship with her. If a legal marriage becomes possible, then praise be to Allah; otherwise, he should seek someone else.