All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Marriage is a great rite of Islam that holds a distinguished status, and thus Islam gave it great concern. It is a long journey so it should not be based on emotions alone that may lead to failure and regret.
It is impermissible for the Muslim woman to marry a non-Muslim man. Allaah, The Exalted, says (what means): {…And do not marry polytheistic men [to your women] until they believe. And a believing slave is better than a polytheist, even though he might please you. Those invite [you] to the Fire, but Allaah invites to Paradise and to forgiveness, by His permission.} [Quran 2:221]
We have to alert you that some non-Muslim men might pretend to embrace Islam just to marry a Muslim woman and when the lie is discovered later on, the Muslim woman is left with two difficult choices, either to carry on with such an illicit relationship or choose disbelief over faith. This often happens and we receive questions about this issue on our website. Therefore, the Muslim woman should not hasten to accept the marriage proposal of a new convert until she verifies his religious commitment so that she would not find out later on that she had been tricked and he was merely pretending to be a good Muslim to get to her. Please refer to Fatwa 133544.
The fact that the person keeps his conversion to Islam a secret does not exempt him from performing the religious obligations and acts of worship secretly without his family's knowledge. The Companions used to go to the mountain passes to perform their prayers secretly. Moreover, if he can announce his conversion to Islam and endure the harm afflicted on him by his family, then he should do so, as he would thus be able to carry out the Islamic acts of worship openly.
If it were assumed that this man has genuinely converted to Islam, became a good and religiously-committed Muslim, and observed the manifest religious obligations, then it is impermissible for him to conduct the marriage in a pagan temple or observe any pagan rituals, even if he does not believe in them. This is prohibited and constitutes imitation of the non-Muslims. In fact, such an act may lure the doer into disbelief.
We advise you, dear sister, to make sure that he is a good and righteous Muslim before marriage. The most manifest signs to look for is his performing of the prayers; and then you may marry him and you should conduct the marriage contract according to the Islamic revealed law. If you fail to verify his religiosity, you are advised to disregard this marriage proposal and look for a pious and devout Muslim man who lives in an Islamic environment and who can help you be obedient to your Lord. It should be noted that it is permissible for the Muslim woman to look for a pious husband. For more benefit, please refer to Fatwa 82471.
Allaah Knows best.