As for one who professes and observes Islam but harbours unbelief without publicly declaring it is not a murtadd, but a munafiq or dissimulator.

The munafiq is not a kafir in the eyes of the Law and must be treated as a Muslim up to and including burial rites and inheritance status, while the murtadd is a kafir in the eyes of the Law and is subject to the penal law (hadd) that applies to the murtadd as enforced only by the Islamic state.

It is forbidden for individuals to enforce any penal law or act of war whatsoever whether in the presence or in the absence of an Islamic state except by lawful mandate, but the latter can be de facto, as in the case of a people’s legitimate defense against aggression.

One who professes Islam without observing its obligations and prohibitions nor harboring unbelief is neither a murtadd nor a munafiq nor a kafir but a fasiq or depraved person — may Allah guide us and you.