What is the ruling on residing in non-Muslim countries in general, and for someone who wishes to acquire knowledge not available in his own country in particular? And what is your advice to Muslim youth residing in Europe?

This worldly life is a realm of trials, and its passing and enjoyments are swift. A single moment in the Fire makes one forget the greatest of blessings. Therefore, one must be wary of sins and hasten to repentance before it is too late, for Allah does not abandon those who repent. Among the things that aid in repentance is leaving non-Muslim lands if you are unable to practice your religion there, and seeking a Muslim country, following the example of the man who killed ninety-nine souls, who was guided to a righteous land to repent.