Morality exists. God explains it.
Objective moral values exist
Certain actions—like lying just for fun, or even more sinister, harming a child merely for one's own pleasure—are universally wrong, not just socially or culturally disliked. These moral truths seem to exist independently of human opinion.
Objective moral values require a grounding
If morality is truly objective, it must come from something beyond humans, because human minds and societies are subjective and changing. Without a transcendent source, morality would just be a matter of opinion.
God is the best explanation for objective morality
A perfectly good, moral, and transcendent God provides the foundation for objective moral values. Only a moral lawgiver outside of humanity can account for why some things are truly right or wrong for everyone, everywhere.
To deny God is to saw off the very brach on which morality sits.
Related posts:
The Inescapable “Ought”: Further Reflections on Objective Morality (part 2)