They do so under the mantle of the Old Testament prophets who, by the power of their words, sought to ignite a people to love and loyalty to their God. The prophets seldom succeeded. They called for a new day, complete with images of a new heaven and a new earth. What they often got was more of the same old way of doing things. Prophets of change are seldom welcomed.
Religious groups are by nature conserving communities.
They seek to hold tight to that which has given meaning and clarity to their common life. On the negative side, this nature can become so rigid that it prevents needed changes. That's not an easy assignment. For example, I believe congregations benefit from a strong connection to their denominational heritage. I believe it is important to a congregation's health, unity and engagement in missions to have a loyalty to its denominational offices, colleges and other institutions.