What do the respected Ulama say about those who do not perform Namaz? Are they Kafirs? What do the guided Imams say about this?
الجواب حامدا و مصلیا
Let it be known that, a person’s mere non-performance of Salat only is not the indication or reason for his leaving Islam and entering Kufr, rather, it is not correct to apply the ruling of Kufr on a person, after accepting Islam, until he bears an explicit Kufr concept or utters an explicit Kufr talk. Similarly a person who admits the obligation of Salat but due to some laziness or short-comings does not perform it, is undoubtedly a sinner for leaving the Salat but declaring him as Kafir is a wrong and impermissible act, refraining from which is essential. As for reference made on those Ahadees e Mubaraka, such a person is called so as a matter of warning and not in its real essence.
Allah knows best.