Interior Secretary Gale Norton recently announced a grant of $317,000 to help preserve an aging edifice of historical importance to the nation. Whereupon Americans United for the Separation of Church and State objected. Why? Because the group sees a manifest violation of church and state in the new policy under which the Park Service made the grant. The edifice happens to be Boston's Old North Church, where Paul Revere got the signal that the British were advancing. And the Old North Church still is--as a horrified Barry Lynn, the executive director of Americans United, told reporters--"an active church." Were it inactive, were it one of the dead cathedrals of Europe--if its 150 members had dispersed to other churches--why, in Mr. Lynn's reckoning, the grant would be fine.