A Muslim Woman Getting Married to a Non-Muslim Man
6-5-2001 | IslamWeb
Question:
My cousin's daughter is getting married to a non muslim, in a church with a dinner reception where alcohol and dancing will be plentiful, I know that I will not attend the wedding, however I sent a card with a gift and wrote in it "may Allah guide you both on his path" but when I try to explain to other relatives that it is haram to attend such a wedding, I get comments like: it is a family matter it will look bad if no one goes, you blame the girl (bride) if she does not speak to you anymore, its all the same god, the invitation reads invite you to join with them in asking God's blessing upon this holy union and lots of other lame excuses. The thing that makes me very sad is that no body seem to understand that, yes! we love or family, but we should love Allah and fear Allah more. This child was not raised in an Islamic home, my cousin married a convert who he later divorced and then a second time marries a non muslim and is not a practicing muslim. His first wife (the bride to be mother) was murdered tragically about a year ago. Should I keep hounding them about going to this wedding?
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
It is forbidden for the Muslim woman to get married to a non-Muslim man because non-Muslims should not have any power over the Muslims.
So, you should do your best to nullify this invalid marriage. Try to contact the leaders and Imams of your community and to stop this grave sin. You should make the Sharee’ah ruling over this issue clear to your relatives.
Remind them of Allah, advise them, and tell them that this act is obnoxious and obscene. They should not keep silent as though nothing bad has been done. Tell them that if they participate in this act, they will commit a grave sin.
We hope Allah will guide you all to the right path.
For more benefit on the absolute prohibition for a Muslim woman marrying a non-Muslim man, please refer to Fataawa 90619, 87151, 274252, 124877, 84265 and 88406.
Allah knows best.