private piety

إِنَّمَا تُنذِرُ مَنِ ٱتَّبَعَ ٱلذِّكْرَ وَخَشِىَ ٱلرَّحْمَـٰنَ بِٱلْغَيْبِ ۖ فَبَشِّرْهُ بِمَغْفِرَةٍ وَأَجْرٍ كَرِيمٍ

You can only warn one who follows the message and fears the Most Merciful unseen. So give him good tidings of forgiveness and noble reward.