@ Mehek : -

Allah Says in the Holy Quran Chapter 5 Surah Maidah verse 5 (part):

(Lawful unto the believers in marriage) are (not only) chaste women who are believers but chaste women among the People of the Book (Jews and Christians) revealed before your time, when ye give them their due dowers and desire chastity, not lewdness nor secret intrigues.

Respected brother in Islam, there is an allowance and a permission in Shariah Law for a believer to marry amongst the chaste women of the ‘People of the Book’ (Jews and Christians), if indeed they wish to do so. A marriage between a Muslim man and a (Jewish or) Christian woman would be considered absolutely legal and lawful in the Sight of Shariah Law and in the Sight of Allah Subhanah, even if the Christian woman chose not to revert to Islam before her marriage.