That's not universally correct. Many non-Christians refer to Christ as Christ. Myself, for example. Ghandi as another example. Some say 'Jesus' some say 'Christ.' Muslims often say 'Isa,' particularly Arab Muslims, and some of course use Yeshua or some other equivalent. But the name does carry specific religious significance that many Jews and even many Christians are unaware of. Jesus was His given name, Christ was His title, and He is often known by that particular title even outside of His followers, much as Ghandi is known as Mahatma even though that's not his name, to use him as an example again.