As being an independent organation funded only by individuals and corporates, Make-A-Wish has nothing to do with any religion. 

You can participate as a volunteer to grant a wish for a child who is eligible.

You can also participate by making a Wish Bear which will be given to the children as a gift. 

Learn about volunteer activities at > http://wish.or.kr/html/sub03/sub03_030101.php

Wish Bear making activity > http://wish.or.kr/html/sub04/sub04_0403.php