The attempt made in recent decades by secular thinkers to disengage [the moral principles of western civilization] from their [scripturally based] religious context, in the assurance that they could live a life of their own as a "humanistic" ethic, has resulted in what one writer has called our "cut-flower culture." Cut flowers retain their original beauty and fragrance, but only so long as they retain the vitality that they have drawn from their now severed roots; after that is exhausted, they wither and die. So with freedom, brotherhood, justice, and personal dignity - the values that form the moral foundation of our civilization. Without the life-giving power of the faith out of which they have sprung, they possess neither meaning nor vitality. Morality ungrounded in God is indeed a house built upon sand, unable to stand up against the vagaries of impulse and the brutal pressures of power and self-interest. (Will Herberg, Judaism and Modern Man, as quoted by Rabbi Joseph Telushkin in his book Jewish Wisdom, page 291)
The belief that a society can exist at all, muchless exist morally, without a belief in God is comparable to a contractor believing that he can build a highrise apartment building without digging down to the bedrock first so that he can form a solid and uniform foundation for the structure to sit on. In both cases the end result will be the total collapse of what was intended to be secure.