الجواب حامدا و مصلیا
According to the Ijma (consensus) of the Ummah it is Wajib (obligatory) to keep beard for fist-length. Reducing less than that level, shaving, trimming etc are impermissible and Haram in Shari’a. Therefore it is necessary for the parents and wife of the questioner to refrain from their void and impermissible demands and encourage the questioner in fulfilling the Shar’i obligation. As for the questioner, it is not permissible for him to reduce the length of the beard to less than the fist-length or shave it off etc accepting their aforesaid demands. He should refrain from doing so. Further it is not obligatory to obey the parents in non-Shar’i orders as such.