Our noble Prophet Muhammad (s.a.w.) said, “My community will continue to be blessed as long they enjoin the good and forbid the evil, and help one another in good deeds. When they do not do this, blessings will be withheld from them, and some [evil persons] among them will have hegemony over the others; and they shall have no helper neither on the earth nor in the heaven.”
Enjoining good and forbidding evil are obligatory rituals, whenever the conditions exist, on all believing men and women. Almighty Allah has said in His noble Book:
“There should be a group among you who should be calling (people) to the good, enjoining the good, and forbidding the evil; they are the successful ones.” [1]
He also said,
“The believing men and the believing women are helpers of one another, they enjoin the good and forbid the evil.” [2]
Our noble Prophet Muhammad (s.a.w.) said,
“My community will continue to be blessed as long as they enjoin the good and forbid the evil, and help one another in good deeds. When they do not do this, blessings will be withheld from them, and some [evil persons] among them will have hegemony over the others; and they shall have no helper neither on the earth nor in the heaven.” [3]
These two obligations become more pressing when the person neglecting the good or committing the evil is one of your family members or one of your relatives, as it reads in the Qurqn:
"O you who have faith! Save yourselves and your families from a Fire whose fuel will be people and stones, over which are [assigned] severe and mighty angels, who do not disobey whatever Allah commands them and carry out what they are commanded." [4]
You might find someone among your family members that neglects some obligations or takes them lightly; you might find some of them performing wudhu or tayammum or ghusl incorrectly, or does not purify his body and clothes from impurities correctly. or does not purify his wealth by paying khums and zakat.
You might find someone among your family members committing some sins like masturbation or gambling or drinking intoxicants or eating haram meat or devouring people’s property unlawfully or cheating and stealing.
You might find someone among the women in your family not observing hijab, not concealing her hair.
You might find someone in your family who habitually lies, backbites and infringes upon the rights of others, usurps people’s property, supports the wrong-doers in their unjust activities, and harasses his neighbour, etc.
If you find any such situations, you should enjoin the good and forbid the evil by applying the first two methods: that is, expressing your displeasure at the situation, and then speaking about it. If these two methods do not work, then apply the third method (after asking the permission from the mujtahid): adopting practical [or physical] measures moving from softer to harsher ones. If that person is ignorant of the religious rules, it is your duty to teach them, if they have the intention of learning and acting accordingly.
Notes:
[1] (3:104)
وَلْتَكُن مِّنكُمْ أُمَّةٌ يَدْعُونَ إِلَى الْخَيْرِ وَيَأْمُرُ‌ونَ بِالْمَعْرُ‌وفِ وَيَنْهَوْنَ عَنِ الْمُنكَرِ وَأُولَـٰئِكَ هُمُ الْمُفْلِحُون
[2] (9:71)
وَالْمُؤْمِنُونَ وَالْمُؤْمِنَاتُ بَعْضُهُمْ أَوْلِيَاءُ بَعْضٍ ۚ يَأْمُرُ‌ونَ بِالْمَعْرُ‌وفِ وَيَنْهَوْنَ عَنِ الْمُنكَرِ وَيُقِيمُونَ الصَّلَاةَ وَيُؤْتُونَ الزَّكَاةَ وَيُطِيعُونَ اللَّـهَ وَرَ‌سُولَهُ ۚ أُولَـٰئِكَ سَيَرْ‌حَمُهُمُ اللَّـهُ ۗ إِنَّ اللَّـهَ عَزِيزٌ حَكِيمٌ
[3] Mizanul'Hikma.v 7. P 333.
لا یَزالُ النّاسُ بِخَیرٍ ما أمَروا بِالمَعروفِ و نَهَوا عَنِ المُنکَرِ و تَعاوَنوا عَلَى البِرِّ، فإذا لَم یَفعَلوا ذلکَ نُزِعَت مِنهُمُ البَرَکاتُ، و سُلِّطَ بَعضُهُم عَلى بَعضٍ، و لَم یَکُن لَهُم ناصِرٌ فی الأرضِ و لا فی السَّماءِ
[4] [66:6]
يَا أَيُّهَا الَّذِينَ آمَنُوا قُوا أَنفُسَكُمْ وَأَهْلِيكُمْ نَارً‌ا وَقُودُهَا النَّاسُ وَالْحِجَارَ‌ةُ عَلَيْهَا مَلَائِكَةٌ غِلَاظٌ شِدَادٌ لَّا يَعْصُونَ اللَّـهَ مَا أَمَرَ‌هُمْ وَيَفْعَلُونَ مَا يُؤْمَرُ‌ونَ.