1. Is it permissible for a father to prevent his son from performing congregational prayers in the mosque? 2. What is the ruling on seeing unveiled girls daily in studies? 3. How should one act towards friends who do not pray, with enjoining what is right and forbidding what is wrong? 4. Is dealing with non-hijabi women permissible in the context of studies?

You should review the fatwas regarding a father preventing his son from congregational prayers and mixed-gender education, as well as the ruling on looking at and speaking with women, and the regulations for interacting with them.

As for your friends who do not pray, strive to advise them, enjoin them to good and forbid them from evil. Supplicate to Allah for their guidance, offer them religious booklets and tapes, and take them with you to attend lectures and visit righteous people. Beware of sitting with them without advising them, so that you do not weaken and regress.