What should I do to help my friend who met a girl and wants to marry her despite his family's opposition, and who feigns religious commitment to achieve worldly goals? And what is the ruling on learning Islamic دين for worldly purposes?

One must think well of Muslims and interpret their words and actions in the best possible light, for Allah Almighty says: "O you who have believed, avoid much [negative] assumption. Indeed, some assumption is sin." (Quran 49:12). The principle is to deal with people based on their outward appearances and leave their inner thoughts to Allah, as the Prophet, peace and blessings be upon him, said: "I have not been commanded to bore into the hearts of people or to rip open their bellies."

Therefore, one must think well of the man and not accuse him of studying religion for worldly gains, though it is permissible to advise him and remind him of the importance of making deeds sincere for Allah. As for a man speaking with a woman over the phone or by other means, it is a gateway to temptation and a means to corruption, even if it is about religious matters, because it can be an enticement from Satan and lead to dire consequences. Jurists have explicitly stated the prohibition of speaking with a non-mahram woman without necessity. The esteemed scholar Al-Khadimi said: "Speaking with a young non-mahram woman is not permissible without necessity, as it is a place of suspicion of temptation." Therefore, the friend should be advised to cease speaking with the girl unnecessarily. If he desires to marry her, he should proceed promptly; otherwise, he should turn away from her.