Allaah says (interpretation of the meaning): 

“Men are the protectors and maintainers of women, because Allaah has made one of them to excel the other, and because they spend (to support them) from their means”

[al-Nisa’ 4:34]

This aayah states that the man is the guardian of the woman and is in charge of her. According to a saheeh hadeeth, the Prophet (peace and blessings of Allaah be upon him) said: “The man is the shepherd of the members of his household and is responsible for his flock. Each of you is a shepherd and is responsible for his flock. So the man is a shepherd and is responsible for his flock.” The most important duty of the “shepherd” is to guide his “flock” to obey the commands of Allaah by doing that which Allaah has enjoined and abstaining from that which He has forbidden. In this way he will be fulfilling his duty of enjoining what is good and forbidding what is evil. So the husband has to tell his wife to do that which Allaah has enjoined upon her and he must forbid her to do that which Allaah has prohibited. The greatest duties that the Muslim must fulfil are the five daily prayers and fasting Ramadaan. These are two of the pillars of Islam. The husband must tell his wife to do these things and to observe these two pillars regularly. It is not permissible for him to be careless in this matter. The same applies to all other obligatory duties. He must also forbid her to do that which Allaah has forbidden, whether it is words or deeds. If he sees that she is responding and obeying, then that is what is required. But if she persists in disobeying then the Muslim man should not stay with her, rather he has to divorce her. How can a Muslim be pleased with a wife who does not pray or who misses some of the prayers, or does not fast in Ramadaan? This is something that is not befitting for a Muslim. Allaah says (interpretation of the meaning): 

“The believers, men and women, are Awliyaa’ (helpers, supporters, friends, protectors) of one another; they enjoin (on the people) Al‑Ma‘roof (i.e. Islamic Monotheism and all that Islam orders one to do), and forbid (people) from Al‑Munkar (i.e. polytheism and disbelief of all kinds, and all that Islam has forbidden); they perform As-Salaah (Iqaamat-as-Salaah), and give the Zakaah, and obey Allaah and His Messenger. Allaah will have His Mercy on them. Surely, Allaah is All-Mighty, All-Wise”[al-Tawbah 9:71]

Whoever does his duty of enjoining what is good and forbidding what is evil has freed himself from blame and is safe from the punishment of Allaah. But whoever is careless and negligent is exposing himself to the threat which Allaah has issued to those who neglect this duty. Allaah says (interpretation of the meaning): 

“Those among the Children of Israel who disbelieved were cursed by the tongue of Dawood (David) and ‘Eesa (Jesus), son of Maryam (Mary). That was because they disobeyed (Allaah and the Messengers) and were ever transgressing beyond bounds.

79. They used not to forbid one another from Al-Munkar (wrong, evildoing, sins, polytheism, disbelief) which they committed. Vile indeed was what they used to do”

[al-Maa'idah 5:78-79] 

“O you who believe! Take care of your ownselves. If you follow the (right) guidance [and enjoin what is right (Islamic Monotheism and all that Islam orders one to do) and forbid what is wrong (polytheism, disbelief and all that Islam has forbidden)] no hurt can come to you from those who are in error”[al-Maa'idah 5:105]

The mufassiroon said that “If you follow the (right) guidance” means, if you fulfil your duty of enjoining what is good and forbidding what is evil.