Hi Lance,
Excellent thread IMO.
Many in the West construe Islam as being monolithic, but this is a false conception, for much diversity exists and has existed in Islam. Further, like Catholicism, Islam has produced many “saintly” people. I would like to recommend a few books on this topic:
Muslim Saints and Mystics by Farid al-Din Attar (trans. A. J. Arberry)
*Islamic Spirituality – Foundations *ed. by Seyyed Hossein Nasr
*Islamic Spirituality – Manifestations *ed. by Seyyed Hossein Nasr
For a more intellectual approach:
*Islam and Other Faiths *by Ismail Raji al-Faruqi
Grace and peace,
David