He had such a poignant way of describing mythology and religious themes that it gave one insights that you might not have ever considered on your own. His description about the binary nature of our own Judeo/Christian traditions (good versus evil, sin and atonement, etc) as contrasted to other religious traditions was quite enlightening to me. Here's a good sample of the thought provoking conversation between Joseph Campbell and Bill Moyers for anyone who has never seen the original "Power of Myth" PBS series. Many libraries carry a DVD copy of the interviews.

I liked the way he explained God as a metaphor, not to be taken literally, but in a literary sense, to understand the greater story. And also how he showed the similarities to so many myths and religions that came before the current Judeo-Christian-Islamic faiths. His work definitely had an impact on my way of thinking about religion.

Joseph Campbell had such a beautiful way of expressing his vast array of knowledge. I'm just now rereading "The Power of Myth". Amazing man!