@Fatihah,
Nice to hear from a potential debater ! I think however you need to understand that even the phrase "
true message of Islam" is problematic since assumes the meaning of "truth" to be axiomatic. For a philosophical pragmatist for example, "truth" merely equates to "what works" from a physical, psychological or sociological point of view, with no precedence assumed in either domain. This viewpoint immediately removes "the divinity" angle from religion and thereby also removes its authoritative aspects.
Now I have given only one debating position which Muslims find almost impossible to handle. No doubt there are others. So the question seems to be whether Muslims can hold their religion at arm's length in order to critically examine it, or whether such an examination is by definition a betrayal of the very term "Islam".