What should a young man do to marry the girl he loves, fearing that his heart may waver with waiting, especially since her father will not agree to their marriage for another four or five years, as they are both still students and he has not yet started working?

If you love this girl, then marriage is the best guidance for those who love each other, for the Prophet, peace be upon him, said: "Nothing like marriage has been seen for those who love each other." And studying does not prevent marriage if you are able to bear its expenses and the sustenance of your family. So try to convince the girl's family. If that is not possible, then you must maintain chastity and be patient until Allah enriches you from His bounty, as Allah Almighty commanded: "And let those who find not [the means for] marriage abstain [from sin] until Allah enriches them from His bounty." And be keen on what helps you maintain chastity, such as fasting and lowering your gaze, for Allah Almighty said: "Tell the believing men to reduce [some] of their vision and guard their private parts." And for the Prophet, peace be upon him, said: "O young men, whoever among you can afford to marry, let him marry, for it is more effective in lowering the gaze and guarding the private parts. And whoever cannot afford it, let him fast, for it will be a shield for him."