Now, I am not an expert on Islam. I haven't even read the whole of the Qur'an. I am a Christian and I don't believe that all religions are "the same" or that all religions are true. I believe that in Jesus we can see God's self-revelation and that following him is the way to most fully experience the love and grace of God. Still, I do believe that one can find truth within virtually all religions. I believe that all religions reflect something built into human beings that drives us to seek God. I also believe that if Christianity is "most true" that we Christians have done a very poor job of representing Jesus to the rest of the world (but that is another post isn't it?)
I am saddened when my brothers and sisters of any stripe build walls that label people as "other" when Jesus spent all of his time and energy breaking down walls. I am saddened when Christians are so filled with hubris that they think they have all of the answers and nobody else brings anything of value to the table. I am reminded of Paul's words to the Corinthians...
1 Cor. 13:9-10, 12-13 (The Message Bible)
 We know only a portion of the truth, and what we say about God is always incomplete.  But when the Complete arrives, our incompletes will be canceled.
 We don't yet see things clearly. We're squinting in a fog, peering through a mist. But it won't be long before the weather clears and the sun shines bright! We'll see it all then, see it all as clearly as God sees us, knowing him directly just as he knows us!  But for right now, until that completeness, we have three things to do to lead us toward that consummation: Trust steadily in God, hope unswervingly, love extravagantly. And the best of the three is love.
Wouldn't be wonderful if we enter any dialogue with others with that mindset? We don't know it all and what we see, we see indistinctly... and for that reason, we trust, we hope, and we love extravagantly!