Can a Muslim man marry a Non-Muslim woman?
A muslim man cannot marry an athiest. The Cow 2:221 (Asad) AND DO NOT marry women who ascribe divinity to aught beside God ere they attain to [true] belief: for any believing bondwoman [of God] [208] is certainly better than a woman who ascribes divinity to aught beside God, even though she please you greatly. And do not give your women in marriage to men who ascribe divinity to aught beside God ere they attain to [true] belief: for- any believing bondman [of God] is certainly better than a man who ascribes divinity to aught beside God, even though he please you greatly. [Such as] these invite unto the fire, whereas God invites unto paradise, and unto [the achievement of] forgiveness by His leave; and He makes clear His messages unto mankind, so that they might bear them in mind.
A Muslim man can marry a woman of one of the religions that received God’s Message prior to its being delivered to Muhammed (pbuh) — that is, Christians and Jews. Most British subjects are baptised (“christened”) routinely as babies: if you were christened in this way then you are nominally Christian. You will be able to marry on that basis. However, you would be extremely ill-advised to repudiate Christianity in any vocal way, until after you return to the United States.
