What is the ruling regarding a Muslim who lives next to the mosque, but rarely performs prayer in it? This person also hearts his nephew because he commands him to drag his garment below the ankles and to shake hands with women, even though his nephew is following the Sunnah.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger. 

The person must stop telling his nephew to do what is evil because this is a characteristic of the hypocrites.  Allaah Says (what means): {The hypocrite men and hypocrite women are of one another. They enjoin what is wrong and forbid what is right and close their hands. They have forgotten Allaah, so He has forgotten them [accordingly]. Indeed, the hypocrites - it is they who are the defiantly disobedient.}[Quran 9:67] 

He also has to perform prayer in congregation unless he has a valid Islamic concession. His nephew should treat him kindly and advise him as the Prophet, sallallaahu ‘alayhi wa sallam, told us that the essence of religion (Islam) is to offer sincere advice.  [Al-Bukhari and others] 

Given the fact that people are always inclined to those who treat them kindly and detest those who wrong them, you should act leniently with him and stay away from harshness.  Allaah Says (what means):

·        {And if you had been rude [in speech] and harsh in heart, they would have disbanded from about you.}[Quran 3:159]

·        {And endure with patience whatever people may say against (you) and avoid them with a comely avoidance}[Quran 73:10]

Also see Fatwa 82264. To learn about congregational prayer, see Fataawa 84967 and 86901. To learn about dragging the garment below the ankles (for men), see Fatwa 91026. To learn about men and women shaking hands, see Fataawa 82318and 84011.

Allaah Knows best.