Munaafiq, murtad, kitaabi, mushrik, dahriyyah, muattil and zindeeq
Every person who is not a Muslim is described in the Shariah as a Kaafir.
One who verbally claims to be a Muslim, but in his heart is not so, is termed a Munaafiq.
A Muslim who renounces Islam is termed a murtad.
One who subscribes to or believes in more than one Divine Being is termed a mushrik. one who associates another as a partner with Allah is also termed a mushrik.
One who follows a previously revealed, Divine religion which has been abrogated, is termed a kitaabi, e.g. Jews and Christians.
One who believes in the eternity of time and ascribes creation to time is termed dahriyyah.
One who denies the existence of the Creator is termed a Muattil (atheist).
One who acknowledges the Nubuwwat of Rasulullah (sallallahu alayhi wasallam) and accepts the shiaar (salient features, e.g. Salaat, Haj) of Islam, but at the same time adheres to belief which are unanimously branded as kufr in the Shariah.
According to this definition the term Zindeeq will apply to all persons who proclaim themselves to be Muslims while at the same time prescribing to kufr beliefs. The majority of baatil sects fall in this category of kufr.
Hadhrat Umar (Radhiallahu Anhu) embraced Islam on the morning of Jumuah (Friday). The Islam of Hadhrat Umar (Radhiallahu Anhu) was a terrible blow to the morale of the disbelievers. After the Islam of Hadhrat Umar (Radhiallahu Anhu), the Muslims started performing their Salaah openly in the Haram. Hadhrat Abdullah bin Mas’ood (Radhiallahu Anhu) says: “The Islam of Umar was a great triumph, his emigration to Madinah Tayyibah a tremendous reinforcement, and his accession to the Khilaafat a great blessing for the Muslims.