In Acts 19 we see a group of 12 men who were not given the complete gospel. They apparently left Palestine after hearing the message of repentance preached by John the Baptist and then relocated to Ephesus. Believing in an incomplete or incorrect gospel cannot save. Paul recognized this and preached the true gospel to these men who had faith, only their faith was not rightly placed in the person and work of Jesus Christ. It is important that Christians know Jesus intimately and accurately, so that we represent him rightly. With so many false gospels and misunderstandings about Jesus in the world, it is vital that we know Jesus as he has revealed himself through the bible. For it is only the Jesus of the bible that saves.