Sorry but costume partys with a bible theme? Borinnnngggg. Besides everyone looks like they are in robes and no one really knows who anyone is anyway. DON"T DO BIBLE THEME PARTYS PEOPLE.
Around 91'ish I was invited to a graduation party at a rented hall for all the teenagers that were graduating. It was a chance for all the young people to hang out, of course, supervised...it was a costume party. We all had fun and everyone wore whatever they wanted. My friend back then wore the skin tight cat suit from batman, someone else was the joker, one couple wore the beauty and the beast costume. They had a costume contest and the beauty and the beast won. They played music, dancing, we had a water ballon fight towards the end of the night. It was great. Although some of the JW's that were not invited (on purpose, because they are uptight) were so offended that a week later they had a "special talk" about get-togethers and dressing in charactors. Funny cause if they were not at the party how would they know what went on anyway?
I say, have a party. Make it halloween. Obviously your spouse wants to do it. Why are JW's so afraid of the supernatural anyway? Again, it's fear that runs the organization. Good luck. I just bought some halloween decor today...woohoo fun