Morality is a neat cover for foul venom, but it does not alter the fact that the heart is vile, and the man himself is under damnation. Men will be damned with good works as well as without them, if they make them their confidence (rather than Jesus Christ).
If Jesus sets the divine standard for morality, I could now have an unwavering foundation for my choices and decisions, rather than basing them on the ever-shifting sands of expediency and self-centeredness.
The absence of the true Light means moral Death. The darkness of the natural world to the intellect is not all. What history testifies to is, first the partial, and then the total eclipse of virtue that always follows the abandonment of belief in a personal God.