John Macquarrie FBA TD was a Scottish-born theologian and philosopher. Timothy Bradshaw has described Macquarrie as "unquestionably Anglicanism's most distinguished systematic theologian in the second half of the twentieth century."
This is an odd attempt to promote religious tolerance and discourse through a very uneven survey of the most important figures in the world's great religions. It really didn't work for me. The problem is that, despite many similarities between the "mediators" (i.e., fantastic births, strict moral codes, their basic humanity, etc.), their treatment is uneven and I question why some were even included. While the essays regarding Confucius, Buddha and Socrates were excellent, the bits about Moses (who, according to this book, apparently might have been Egyptian and murdered by the Israelites!) and Krishna were only mildly informative, Jesus only got a drive-by and I have absolutely no idea what Zoroaster and Lao-zu believed. Further, while it seems clear that Moses, Zoroaster, Krishna, Jesus and Muhammad acted as mediators between man and god, I have no idea why Lao-zu, Confucius or Socrates were included in this list since they seem more like ambassadors to the self than the divine. On the plus side, the author, a Catholic priest, is very even-handed and non-judgmental in his examination of the mediators, although he seemed to go after Muhammad a little harder than the others (e.g., duty to God trumps human ethics and morality). Anyway, there is probably a better introduction to the world faiths and/or "mediators" somewhere out there.