RE: If you say you believe the Christen Gospel you are implying Mohammad was (at best) a liar.
Well, what else can it mean?
Islam teaches that Jesus DID NOT die on the cross while to Christians, this is the center of their message.
Both can’t be correct on this issue.
Either the Gospels are a lie or the Koran is. Both can’t be correct.
So, being a Christian INHERENTLY means you believe the Koran is lying about Jesus, which means that your faith INSULT Islam ( even when you don’t say it out loud ).
Anybody who thinks it through would come to the same conclusion.
You can bet the people who are advocating for laws outlawing insults to the prophet (except for the useful idiots) have thought this through.