The problem with that position, is the the state actively denies the ability to carry out that mission. They will send men with guns to kill anyone who attempts to help widows and orphans without the explicit permission of the State.
In order to even attempt to perform their mission, they must bow to Caesar. This particular win will last about a week. A small wording change will effectively ban them again, and they'll be forced back into court.
That's not true in this case. Nobody is saying a religious organization can't be involved in foster-care situations (the Amish probably do this all the time). In the Philadelphia case, the city tried to exclude these religious organizations from CITY-RUN and CITY-FUNDED foster care arrangements.
Call me a heartless bastard if you will, but anyone involved in foster care who collects taxpayer money for the kids they house isn't really exercising true Christian charity.