Pretty much nails the point, GC. At a fundamental level one cannot simply believe in Jesus as an abstract person with incorrect characteristics, be saved, and then have the blanks filled in and the errors corrected after the fact. Otherwise it would be perfectly acceptable to get people to confess faith in Jesus Corona so that God could then exercise His sovereignty over these "believers" and bring them to a right understanding of the real Jesus.
As always, we can hear the gospel from the writings of the Apostles or we can't. Jesus said when others believe in Him through their word they would be saved, too.
John 17: 20 “I do not pray for these alone, but also for those who will[e] believe in Me through their word; 21 that they all may be one, as You, Father, are in Me, and I in You; that they also may be one in Us, that the world may believe that You sent Me."