The truth of the matter is this: Religion, and religious views should hold NO weight in federal law.
Marriage in in itself is not solely christian, therefore, the christian ideologies of marriage should not even be considered when the proposition of homosexual marriage arises.
Also, any argument pertaining to a federal issue, of any kind, should be ignored entirely if stems from any sort of religious text or belief. IE: One could not argue against the teaching of evolution in schools because their religious text states a different theory pertaining to creation.
In essence, if somebody were to use their religion (whether it be hindu, christian, jewish, etc) as a reasoning supporting their claim, it should be ignored entirely, and dropped forthwith.
SEPARATION OF CHURCH AND STATE.