Bulle Shah, a Sufi poet, also popularized by Mr. Rabbi Shergill (bulla ki jaana main kaun..), has always challenged religious rituals in his writings. I came across one of his writings, sung equally enchantingly by Nusrat, and ended up wasting (not really, only worldly) 3 hours on it. I could find a decent english translation here for you (spanks disabled). You are also welcome to step into the whirlpool Nusrat creates, Bulla sitting at the eye of it.
Philosophical response to the poem pending, yours truly cannot write but just listen right now.
-G Singh, San Jose, 29th June, 2008