Generally, if the sex of the Card art is male, then the card is played male, if the art is female, the card is played female. I believe that goes with "generic" cards as well such as "Elders of Jerusalem" etc.
And just in case you are confused, I used sex but some card identifiers use the word "gender" (like the promo "self") , but to clarify, as far as I know, Sex and Gender are considered the same thing in Redemption. In other words, I am aware of not instance in Redemption where the cards"gender" is different than its "biological sex" with "biological sex" being the only real point considered.
There is never going to be a case where the cards sex and gender do not align.
And this should not be seen as an "Anti- PC" thing, or an attack on gender rights, its just that, for the purposes of the game, there is never going to be a foreseeable reason why the two should be separated since the Bible never brings up Sex/Gender differences and it never was a factor in any of the bible stories involved.
I will admit that I have not read up much on gender differences and what the bible says, but having read through the bible several times, I cannot think of a situation that specifically addresses gender issues other than possibly homosexuality, nor can I think of one where the situation is even hinted at. But I could be wrong.