Is it permissible to marry a Christian man who has declared his conversion to Islam in name only, without adhering to prayer and fasting, despite the prospective wife's attempts to gradually advise and guide him towards religious commitment?

Merely declaring Islam does not mean a person has become a believer. The soundness of faith requires both speech and action. Speech entails the speech of the heart (belief) and the speech of the tongue (the two declarations of faith). Action entails the action of the heart (intention and sincerity) and the action of the limbs.

The Companions, their successors, and the scholars of Sunnah all agreed that actions are an integral part of faith, and that faith is speech, action, and creed, none of which can substitute for the other. Faith is not merely a verbal declaration without submission and surrender to God's rulings, for Allah Almighty says: "But no, by your Lord, they can have no faith, until they make you [O Muhammad] judge in all disputes between them, and find in themselves no resistance against your decisions, and accept them with full submission."

The inward and the outward are intertwined. Merely declaring the two declarations of faith without acting upon and submitting to the rulings of Islam does not make one a Muslim, for Allah Almighty says: "And they say, 'We believe in Allah and in the Messenger, and we obey'; then a party of them turn away after that. And those are not believers."

Therefore, it is not permissible to marry this young man because he has not entered Islam, nor has faith entered his heart, for Allah Almighty says: "And do not marry polytheistic women until they believe." And the woman is not obligated to invite this man [to Islam] because he is a stranger to her.