The word pluralism is used in several senses. First of all it refers simply to the fact that there exists a plurality of cultures, religions, ethnic groups and life styles in our society. This may be termed factual or empirical pluralism and makes no judgement as to whether this state of affairs is good or bad. It simply describes a reality which we have to accept.
Essential to the existence of this pluralism is religious toleration. Where there is no toleration, as in certain Muslim countries, there can be no pluralism. Toleration was introduced by Protestant Christians through the Act of Toleration of 1689 in England. They believed that the truth of the Bible was sufficient to defend Protestant Christianity from other belief systems, which were by definition erroneous. In the following century the First Amendment of the Constitution of the USA guaranteed freedom of religion as a fundamental human right, without establishing any one denomination. This was based on the transcendent truth of man's nature as created by God. Now the basis for toleration is exactly the opposite - the conviction that there is no such thing as absolute truth. All is relative and thus each belief system is valid for its adherents.
Many Christians have not fully come to terms with this change. They persist in thinking that we still live in a basically Christian country, and are shocked when they see and hear evidence to the contrary. Some try to ignore what is going on and attempt to retreat into the comfort of a Christian ghetto. Others protest strongly against what they see as a betrayal of our Christian heritage, yet without understanding the enormity of the problem and without communicating meaningfully with those they seek to influence.