Read the article "Pastor Apologizes to His Denomination for Role in Sandy Hook Interfaith Service" found at: http://www.nytimes.com/2013/02/08/nyregion/lutheran-pastor-explains-role-in-sandy-hook-interfaith-service.html
Where is the line between respecting different faiths, and endorsing different faiths? Does worshiping together cross it? If not, what would be too far?