Thank you for your reply. But I still wonder if it is a sin. I agree with you when you say about the wrong and right part and that is all I can say...but I wonder if it is a sin.

Yes, a woman will follow the religion of the man she marries. But nowadays there are some who stay the way they are and even give their children two names of both their religion.

But which will the poor child follow? Will he become a rojak?

'Rojak' is a food in Singapore which is a mixture of many fruits, sauce, sugar, salt, chillie etc