What is the best way to deal with a 20-year-old brother who has completely stopped praying, including Friday prayers, and shows no interest in advice and repeated attempts by his family to persuade him, and how can he be encouraged to commit to prayer?

The questioner should continue to advise her brother and remind him of the danger of abandoning prayer, and clarify to him that it is considered disbelief by many scholars, and that he is exposing himself to the wrath and punishment of Allah. She should utilize beneficial booklets and tapes. If she knows that shunning him would benefit him, then she should shun him; otherwise, she should continue to advise him and supplicate for his guidance.