One of the most common observations made by opponents of religion is that we don’t need God in order to have a coherent and integral morality.
Atheists and agnostics are extremely sensitive to the charge that the rejection of God will conduce automatically to moral chaos. Consequently, they argue that a robust sense of ethics can be grounded in the consensus of the human community over time or in the intuitions and sensibilities of decent people, etc.
What I would like to do is lay out, in very brief compass, the Catholic understanding of the relationship between morality and the existence of God and to show, thereby, why it is indispensably important for a society that wishes to maintain its moral integrity to maintain, at the same time, a vibrant belief in God.