Why do religious organizations only help people of their faith?

like durring world war 2 when the jews where getting killed the cathlic church was given information about the killings that where taking place with the jews and did not speek out because they where not cathlics. but they did speek out when the nazi's where killing mentally disabled cathlics. or how christain organizations only help christain kids, like their is such a thing as a christain kid. very young kids do not know enough about faith and religion to know what they are or make a decision on it. i would think these organizations would just help those in need instead of just helping people of their faith.