We all want Joy. We all want Love. We all want Peace-of-Mind. To get them, a profound understanding of them helps. Spinoza's insights help provide such understanding.
The biggest issue non-biblicists have is creation vs. evolution. The most accurate debate we have encountered around this issue can be found at this site.
Kant argued that moral requirements are based on a standard of rationality he dubbed the “Categorical Imperative” (CI). Immorality thus involves a violation of the CI and is thereby irrational.