Historically the belief in heaven and the belief in utopia are like compensatory buckets in a well: when one goes down the other comes up. When the classic religions decayed, communistic agitation rose in Athens (430 B.C.), and revolution began in Rome (133 B.C.); when these movements failed, resurrection faiths succeeded, culminating in Christianity; when, in our eighteenth century, Christian belief weakened, communism reappeared. In this perspective the future of religion is secure.