Of this I fully agree. I see new believers who have just heard carp in their life before Christ and take some as "gospel". We've dealt with people who have watched Creflo Dollar, Joyce Meyer and Joel Osteen and believe that to be what Christianity is about. Everyone has heard the "God is like an egg" or "God is like water" analogies and when we point out the shortcomings in those ideas, they seem shocked. But this is where discipleship comes in. They need to be taught just as if they never heard any of it before.
If you deny who Jesus is you deny the gospel.