How can a person
    still be Muslim if he reaches the point of being executed and still insists on not
    praying?
Question

                Dear Shaykh May Allaah increase you in
      good, the issue of the hukm on the one abandoning the salah has differences of opinions
      amongst the people of truth. After reading your fatawa and knowing the opinions of the
      salaf like the well known view of Imaam Ahmad (ra), what seems to be the truth based upon
      evidences is that abandoning the salah is Kufr which takes one outside the fold of Islaam.
      However in the opposing argument there is something I do not understand, Imaaam Shafiee
      and Imaam Malik (ra) and others said, 'To be killed but not kaafir', so he would be buried
      amongst the muslims. But if a person had to be killed for abandoning the salah having been
      given chance to repent how can he still be a muslim? He has prefered death over praying so
      by necessity must be a Kaafir. Please explain. JazakAllaahu Khairan
Praise be to Allah.This is a very good question, but those who say that such a 
  person is not a kaafir do not have a good answer. Shaykh al-Islam ibn Taymiyah 
  (may Allaah have mercy on him) noted that this confusion arose among the later 
  fuqahaa, because this was not known among the Sahaabah, may Allaah have 
  mercy on them. As the questioner says, it is not possible that a person who 
  is threatened with execution for not praying would choose death over prayer 
  if there was even an atoms weight of Islam in his heart. This confusion 
  does not arise if we say that the one who does not pray is a kaafir. If we read 
  what Shaykh al-Islam Ibn Taymiyah said about this matter, this will dispel any 
  confusion.
He (may Allaah have mercy on him) said:
In the case of one who believes that prayer is obligatory yet 
  still persists in not praying, the fuqahaa who have studied the matter 
  in detail mentioned a number of points:
The first of them is this point, which was stated by the majority 
  of them, Maalik, Al-Shaafai and Ahmad: if a person persists until he is 
  killed, is he killed as a kaafir and an apostate, or as a sinful Muslim like 
  other sinful Muslims, as stated in the two well-known views reported from Ahmad? 
  Such detailed discussion was not reported from the Sahaabah, and is excessive 
  and futile.
If the person believes in his heart that prayer is obligatory, 
  this will not allow him to persist in not doing it until he is executed. Such 
  a thing is not known among the sons of Adam, and has never happened in Islam. 
  It is unheard of for a person to believe that it is obligatory and to be told, 
  If you do not pray we will execute you and then to persist in not 
  doing it even though he believes it is obligatory. This has never happened in 
  Islam.
When a person refrains from praying until he is executed, he 
  does not really believe in his heart that it is obligatory and was not doing 
  it, so he is a kaafir, according to the consensus of the Muslims, as it was 
  stated in many reports that the Sahaabah would consider such a person to be 
  a kaafir. This is also indicated by the saheeh texts, such as the ahadeeth of 
  the Prophet  (peace and blessings of Allaah be upon 
  him): 
Nothing stands between a person and Kufr except his giving 
  up prayer (narrated by Muslim).
The covenant that separates us from them is prayer, and 
  whoever gives up prayer has become a kaafir.
Abd-Allaah ibn Shaqeeq said: The companions of 
  Muhammad did not think that giving up any deed would make a person a kaafir 
   apart from giving up prayer.
Whoever persists in not praying and never prostrated to Allaah 
  at all until he dies, can never be a Muslim who believes that prayer is obligatory. 
  Believing that it is obligatory and that the person who does not do it deserves 
  to be executed is sufficient motive to make a person do it, for if a person 
  has the motive and ability to do something, it should be done. If he is able 
  to do it but he never does it, this indicates that the motive is not present 
  in his case.
(Majmoo al-Fataawa, 22/47-49)
Please also refer to Question #2182
And Allaah knows best.