The 12 taught the kingdom gospel.So what message did the Apostles bring to the lost ? Was it their own messages or the same message Jesus taught that God with held the meaning OF ? There are not gospels there is only ONE gospel.
Faith with works.
Sent to baptize.
Paul taught the grace gospel.
Faith without works.
Was not sent to baptize.
And many other differences
Or as you may hear on several occasions, "Things that differ are not the same".