Unto every one of you We have appointed a law and way of life. And if God had so willed He could surely have made you all one single community; but in order to test you by means of what He has vouchsafed unto you. Vie, then, with one another in doing good works! Unto God you all must return; and then He will make you understand all that on which you were wont to differ.
My interpretation of that is this: All followers of a given faith (at least, an Abrahamic faith) who follow what God has handed down to their particular belief community are in the right, even if what they follow differs from what God has handed down to a different belief community. God created these differences as a test of faith, to see who might stray from what God has told them is the "one true way" (or whatever you wish to call it) in favor of what others claim was revealed to them as the "one true way"; the differences will be resolved and explained as part of a believer's reward in Heaven.
My professor, who isn't so much a scholar of Islam as she is a scholar of Middle Eastern history, admits that she's not entirely sure of the correct interpretation, so I ask those of you here who are in the know: am I way off base, or am I heading down the right track?
I'm not a candidate for conversion or anything, so please don't waste your time; but that doesn't mean I'm not interested in understanding Islam's teachings.

