Is it permissible for him to sell gifts that have to do with kaafir festivals?


There is a factory that makes glass gifts, such as perfume bottles and candlesticks and exports them to other countries. I have been offered a position with responsibility for exports, but the factory will ask me to make some gifts that are just for Christian holidays (Christmas) such as crosses and images.
Is this work permissible? I fear Allaah now that I have been blessed with some knowledge and have memorized His Book.