"The purpose of this book is positive and constructive, although it may not at first appear such to the reader whose inherited beliefs are freely challenged. But let the reader ponder the fact that the deepest spiritual life has always concerned itself with the appreciation and maintenance of values. He who acknowledges, and wishes to further, human values cannot be said to be irreligious or unspiritual.

"The center of gravity of religion has been openly changing for some time now from supernaturalism to what may best be called a humanistic naturalism. The history of this change is traced in many of the chapters of the book. There have been many steps forward in the past, for every age must possess its own religion, a religion concordant with its knowledge and expressive of its problems and aims. The sincerity and adequacy with which this necessary task is done measures the spiritual greatness of the particular age.

"I have called the book The Next Step in Religion because the time is ripe for one of the great steps forward. The setting of religion must be adjusted to man's knowledge. Let it not be feared that man's spiritual life will be injured thereby. Rather will it be made saner, healthier and more creative."