Can a non practicing Muslim be a martyr?

Belief is not something that we claim. I cannot claim to be a Muslim just by speech. The kuffar of Quraysh is a demonstrated example as they had belief in certain aspects of ‘aqeedah, but their belief in those certain things did not make them believers. It is important to note that belief is comprised of three things, they include:

1. Statement- We state our belief
2. Action- We act on our belief
3. The belief in the heart, the conviction in the heart of teachings of Allah and Rasool .

Furthermore, we don’t have the authority to say that an individual is a kaafir either, except for not praying, leaving other acts of worship out of laziness is not considered disbelief either.

We give naseehah and do da’wah to our best; so to say if that person is a martyr or not Allah knows best. In this case we don’t know who is and who isn’t a martyr, but we do know the signs of people that usually fall under categories of martyrdom.

Scholars have difference of opinion on the permissibility of calling someone a martyr.

In Ṣaḥeeh Al Bukhari there is a chapter entitled, “One should not say that someone is a martyr.” In this chapter Al Bukahri relates a statement of the Prophet (sallallaahu alaihi wa sallam) wherein he said, “God knows best who fights in His way and who speaks in His way [meaning in His cause].”

And Allah knows best.