السلام عليكم ورحمة الله وبركاته My parents spread hadith rejector ideas, explantion of verses and insult Bukhary in family gatherings should I always stay quiet?I already advised them, should I warn about them in private?They believe christians are not kuffars, hijab not wajib, haram only in quran..

Ustadh AbdulAziz al-Haqqan

U did what u could and if u see wisdom in continuing to advise them with kindness and wisdom then do so.