"We do a disservice to people if we water down the Gospel to be amenable to any and all points of view -- even illogical and contrarian -- for then, we give quarter for them to continue in error."

Now that is a legitimate question. That is why I wrote this article - to have this debate.  

What is the gospel exactly? Why is a "Messianic-Muslim" someone who does not accept the gospel until they reject Muhammed as a false prophet? Because your argument reminds me a lot of Christians who claim Adventists have their own "book" too through their own later prophet Ellen White, which they say means we are a non-Christian cult that rejects the gospel. 

Why can't Muhammed be a modern-day Balaam, with a specific message for the Arabs for his own time, fighting in the face of the apostate Catholic-Byzantium empire?