If we have free will, we must CHOOSE good. However, before we know what good is, we must know that bad. An honest examination of evil may be seen as haresy. In order to avoid evil, we must know what evil is.
When we examine what we believe this may lead to us deciding to take a different path than that which spiritual leaders advocate. When we make decisions based on our subjective experiences, logic, or analytical musings, we can arrive at very different conclusions.