Laziness in performing some of the obligatory duties

Q: What is the ruling on one who affirms the oneness of Allah the Exalted but is lazy in performing some of the obligatory duties?
A: His faith is deficient. Likewise, one who commits some sins has his faith diminished according to the people of the Sunnah and the community; because they say that faith is speech, action, and belief, and it increases with obedience and decreases with disobedience. An example of this is leaving the fast of Ramadan without an excuse, or part of it; this is a major sin that diminishes and weakens faith, and some scholars declare him a disbeliever for it.
But the correct view is: he is not declared a disbeliever for it as long as he acknowledges its obligation, but he broke the fast on some days out of negligence and laziness.
Likewise, if he delays zakah from its time out of negligence or leaves it out, it is a sin and a weakness in faith, and some scholars declare him a disbeliever for leaving it.
Likewise, if he severs his family ties or is undutiful to his parents, this is a deficiency in faith and a weakness in it, and so are the rest of the sins.
As for leaving the prayer, it contradicts faith and necessitates apostasy, even if he does not deny its obligation, according to the stronger of the two opinions of the scholars; due to the saying of the Prophet (peace and blessings be upon him): . And his saying (peace and blessings be upon him): in other hadiths that indicate this.