One of the biggest problems Christianity has to deal with is the fact that it has created the myth around itself that it is a stand alone religion. i.e. If the idea isn't Christian, it can't be good. This concept is clearly shown in this illustration from an old Time magazine. In this picture it is the American Conservative Protestants  who are shown to be firmly rooted in the Bible. Nothing wrong with that of course except for the fact that they show no links to the environment they are part of and are supposed to manage and "save".
It is easy to imagine a group of people who pick up their marbles and go home when the other participants in the game insist on playing the game by different rules. Makes us think of the text: 

MAT 10:14 If anyone will not welcome you or listen to your words, shake off the dust from your feet as you leave that house or town.

It is not the image I want my Church to portray.