Very interesting question. Some social scientists believe that religion is a force of conservation because it gives a specific people a blueprint or plan to follow and on which to base their lives which emerges from a specific historical time period. Because of this, they argue, following the "blueprint" or code of conduct will make it difficult for these people to move with the times and adapt and show flexibility to changing circumstances. A classic case would be Islam, that some critics would argue is still trapped in a previous century because of its harsh legislation and rules. However, it is important to note that the same criticism has been levelled at Christianity and every other major religion.
Religions therefore present us with a set of rules and laws that must be followed. They demand obedience or threaten some form of eternal punishment. Yet because of this they lack flexibility and responsiveness to a rapidly changing world with very different circumstances from when these religions began. You also might like to think about the way that the conservative political forces in America are often religious, trying to maintain and preserve social institutions such as "the family" being based around a heterosexual marriage, rather than any different, more modern interpretations of "family."