Regarding Ehrman’s claim that all manuscripts are filled with errors; we noted the kinds of errors that are to be found in the copies. The vast majority of them are quite inconsequential. And less than 1 percent of all textual variants both affect the meaning of that verse (though none affects a core doctrine) and have some plausibility of authenticity. 
Darrell L. Bock and Daniel B. Wallace, Dethroning Jesus: Exposing Popular Culture’s Quest to Unseat the Biblical Christ, (Nashville, TN.: Thomas Nelson, 2007), 71. Print.