If a person was a Christian and converted for Marriage to Islam, never followed Islam but continued following Christianity would they be considered a non-Muslim or a Murtad?
بسم الله الرحمن الرحيم
There are two possible scenarios;
In the first scenario, if the person recites the Shahada with conviction in his heart, with the intent of accepting Islam that person is a Muslim.
In the second scenario, if the person uttered the Shahada merely to contract the marriage and the intent was not to accept Islam, that person is not a Muslim.
In the first case scenario, the laws of Islam will apply to that person. Thus if he/she denounces Islam after wholeheartedly embracing it that person will be an apostate [murtad]. Hence the laws of apostasy will apply viz. the marriage will be terminated and the couple must be separated. All marital relations will be prohibited as it would be considered fornication and adultery. Children born from such a union will be considered born out of wedlock. The children’s paternity will not be established hence their lineage will be connected to the mother. The couple cannot re-marry unless the apostate re-embraces Islam wholeheartedly.
In the second case scenario where the person did not accept Islam, rather he/she uttered the Shahadah merely for the purpose of marriage, if it was the man then the marriage will not be contracted. This is because the Shariah does not permit the marriage of a Muslim girl to a non-Muslim man. If such a union exists (i.e. Muslim woman and non-Muslim man), the above-mentioned laws will apply.
If it was the woman (who uttered the Shahadah merely for the purpose of marriage), she will not become a Muslim. However, the marriage will be valid as it is permissible for a Muslim man to marry a Christian woman [with conditions stipulated by the Shariah]. Furthermore, the Christian wife will not inherit from her Muslim husband. The husband can make a Wasiyah bequeathing a portion of his wealth to her.
If a man committed apostasy, and died in that state then, his heirs will only inherit from him that portion of wealth owned and possessed by him while being a Muslim and the latter will be distributed to the poor and needy Muslims.
If a woman committed apostasy then the ruling would be different, in that her entire estate i.e. before apostasy as well as after would be inherited by her heirs.
An apostate, whether man or woman, will not inherit from his Muslim family members.
And Allah Ta’āla Knows Best
Mufti Kaleem Muhammad
Darul Iftaa, Jaamia Madinatul Uloom