Those that were persecuted for the Gospel were persecuted for their actions not their beliefs. Ad when one tries to verify the claims of persecutions it soon becomes obvious that they were grossly overblown.
Peter was crucified and all of the Apostles but John who wrote the Book of Revelation, died for the gospel. What was overblown? Why would they spread the gospel and accept persecution for it, if it wasn't true? Their actions that they were persecuted for were directly related to their beliefs.