Muslim man marrying a chaste Christian woman
Question:
I would be most grateful for your help with the following issue.
My daughter is a Christian (Woman of the Book) and she would like to marry a Muslim man and she does not want to change her religion.
They are both living in Singapore and I have been told that in Singapore because the Muslim relogion is not the dominant religion he cannot marry her unless she becomes a Muslim. Is this the case? If it is not, can they both be married in a Muslim wedding service even if my daughter remains a Christian and could the Muslim man also take part in a Christian wedding service after he has been married according to the Muslim tradition. 
I am sorry to submit such a long question but this issue is causing considerable difficulties in our family and I would like to have the correct Muslim law on this issue so I can resolve the problem with the least upset to all. I thank you in anticipation.

Answer:
Praise be to Allaah.  

Islam does not prevent marriage to a Christian woman if she is chaste. Allaah says (interpretation of the meaning): 

“…The food (slaughtered cattle, eatable animals) of the people of the Scripture (Jews and Christians) is lawful to you and yours is lawful to them. (Lawful to you in marriage) are chaste women from the believers and chaste women from those who were given the Scripture (Jews and Christians) before your time when you have given their due Mahr (bridal-money given by the husband to his wife at the time of marriage), desiring chastity (i.e. taking them in legal wedlock) not committing illegal sexual intercourse, nor taking them as girlfriends…”

al-Maa’idah 5:5 

What is meant by chaste women is that they are free (not slaves) and chaste (not loose or immoral). 

See also question no. 2527 

But if a woman is not chaste, and she has boyfriends or lovers with whom she is intimate, then Islam forbids marriage to her, whether she is a Muslim or a woman from among the People of the Book, just as it forbids marriage to a man who has girlfriends or lovers, to protect married life from collapse and to protect against mixing of lineages and to avoid causes of dispute, accusation and suspicion. 

With regard to the Muslim husband attending marriage parties according to the Christian tradition, this is not permissible because there will be many things in these celebrations that are forbidden in Islam, such as free mixing between men and women, listening to music, drinking alcohol, dancing etc. 

In the hadeeth the Prophet (peace and blessings of Allaah be upon him) said: “Whoever believes in Allaah and the Last Day, let him not sit at a table where wine is being drunk.” Narrated by Ahmad, 1/20; al-Bayhaqi, 7/366. Al-Albaani said in al-Irwa’, 7/6: it is saheeh.
We thank you for your noble feelings and this good attitude and your keenness to ask about the Islamic rulings on this matter. 

We ask Allaah to help you and guide you to the religion of Islam. Praise be to Allaah, the Lord of the Worlds.

Islam Q&A