Is it permissible to work as a security guard in a shop in the United Kingdom that sells prohibited products such as alcohol and tobacco? What is the ruling on stopping thieves who steal these products? Is there any advice regarding the difficulty of finding a lawful job in this country?

There is no objection to working as a guard for commercial shops. However, it is forbidden to work in shops that deal with prohibited items, such as selling alcohol and pork, whether as a guard or a salesperson. This is because it entails condoning evil and is considered assisting in sin. "Allah has cursed alcohol, its drinker, its pourer, its seller, its buyer, its presser, the one for whom it is pressed, its carrier, and the one to whom it is carried." A Muslim must seek lawful work and distance themselves from places of evil. Allah Almighty says: (And He has already sent down to you in the Book that when you hear the verses of Allah being denied and ridiculed, do not sit with them until they engage in another conversation. Indeed, in that case, you would be like them) (An-Nisa' 4:140), and (And when you see those who engage in [blasphemous] discourse concerning Our verses, turn away from them until they engage in another conversation) (Al-An'am 6:68), and (And those who do not bear false witness, and when they pass by something foolish, they pass by with dignity) (Al-Furqan 25:72).