Ethics and religion are large and important areas of life. This book explores some of the main philosophical issues linking the two. To show where we're going, I'll first clarify three key ideas: philosophy, ethics, and religion.

Philosophy

We can explore how ethics and religion connect using various disciplines: history, law, anthropology, sociology, literature, biology, philosophy, and so forth. Our philosophical approach rationally debates big questions about ethics and religion. Philosophy is reasoning about the big questions of life.

If you search the Web for “ethics and religion,” the biggest issue is this (with many people arguing yes or no): “Is God the source of morality (so without God we can't have genuine duties)?” This will be a central issue here. This isn't the same issue as “Can atheists have a morality and be good people?” Practically all thinkers answer yes to this. Our issue, rather, is whether morality makes sense without God.

Religious philosophers tend, roughly, to be of two camps. Some see ethics as God's commands (Part I, Chapters 2 and 3), while others see ethics as natural laws that have some independence from God's will (Part II, Chapters 4–6). Both views have evolved sophisticated forms. I'll argue that the best view for religious thinkers is a combination I call divine-preference natural law.

Along the way, we'll get into other issues, such as, “How can we know right from wrong?” “How does morality relate to evolution?” “What does loving-our-neighbor mean?” “How does the golden rule work?” “How are the commandments against stealing, lying, killing, and adultery best understood and defended?” “What duties do we have toward those of other faith perspectives?” “What are our duties toward God?” and “What difference does belief in God make to ethics?”

Part III, on ethics and atheism (Chapters 7 and 8), studies how atheists object on ethical grounds to belief in God and how they view ethics. I'll also respond to their objections.

Philosophy differs from theology. Traditionally and roughly, philosophy uses only human reason, while theology adds divine revelation (perhaps from the Bible or church teaching). We'll mostly stay on the philosophy side of the divide, but sometimes (as in §1.3) we'll wander across the fuzzy border.