The separation of church and state is necessary partly because if religion is good then the state shouldn't interfere with the religious vision or with the religious prophet.
Reinhold NiebuhrThe measure of our rationality determines the degree of vividness with which we appreciate the needs of other life, the extent to which we become conscious of the real character of our own motives and impulses, the ability to harmonize conflicting impulses in our own life and in society, and the capacity to choose adequate means for approved ends.
Reinhold NiebuhrThe scientific observer of the realm of nature is in a sense naturally and inevitably disinterested. At least, nothing in the natural scene can arouse his bias. Furthermore, he stands completely outside of the natural so that his mind, whatever his limitations, approximates pure mind. The observer of the realm of history cannot be disinterested in the same way, for two reasons: first, he must look at history from some locus in history; secondly, he is to a certain degree engaged in its ideological conflicts.
Reinhold Niebuhr