Sinn Fein leader Gerry Adams, right, holds a copy of the Good Friday Agreement with Martin McGuinness, left, as they speak to journalists in the Stormont parliament building in Belfast, Northern Ireland, Oct. 14, 2002. The 20th anniversary of the Good Friday Agreement should be a time of celebration, but Irish church leaders say Brexit raises fears of a return to a hard border between Ireland and Northern Ireland. (CNS/Darren Staples, Reuters)