Muslims appear to be rather too eager in creating different categories for their co-religioinists. One is a Muslim who believes him or herself to be so, whether practising or not.
Some Muslims who adhere to the rituals of religion could also - conceivably - be placed in a non-practising bracket on account of their actions, which contradict and conflict with the substance and essence of true Faith.
Whereas those Muslims who do not actively practice their Faith do, nevertheless, adhere to the real spirit of Islam - through actions. So practising one's religion without also manifesting the acts of true faith is, in actuality, redundant.
People tend to focus upon outward forms, because sometimes appearance is more easily identifiable than reality. However, appearance and reality are often two entirely different things. Thus, a religious person is not only one who performs the rituals of his/her faith, but rather one who believes that faith in God encompasses every act, no matter how great or small.
Ultimately, it is God Who judges according to HIS Knowledge of the human heart.