Is it permissible to marry a girl one has communicated with via Facebook with the aim of supporting her in a religious matter, knowing that this communication has led to developing an attachment to her and love for her religiosity?

If the girl is religious and of good character, then marrying her is recommended and encouraged, for the Prophet, peace and blessings be upon him, said: "So win the one who is religious, you will prosper." And nothing is seen for those who love each other like marriage.

One must hasten to propose to her guardian and complete the marriage, along with performing Istikhara before proceeding. If marriage becomes easy, then praise be to Allah. Otherwise, the relationship with her must be cut off to block the devil's avenue, for an unlawful relationship may lead to sin, as Allah the Almighty said: "O you who have believed, do not follow the footsteps of Satan."