The following is a condensed version of the post.
For most religious Americans
December 25 has become the time that Christians express the joy that comes from a sense of unearned forgiveness and unconditional love. It is a time when they relish the community of believers and family, and they look forward to a future when peace and joy will reign on earth "as they do in heaven" and the lion will lie down with the lamb.
Catholic Church chose December 25th (Winter Solstice in the Julian Calendar) to honor the birthday of the Christ for a very specific reason: It was already a well loved holiday -- a time of revelry, gift giving, and yes, celebrating the birthdays of gods.
Obviously, early Christians were offended. Puritan leader Oliver Cromwell outlawed the celebration in England, and his prohibition against Christmas was kept by the Puritan colonies in the New World.