But though we, or an angel from heaven, preach any other gospel
unto you than that which we have preached unto you, let him be
accursed.
(Galatians 1:8)
Paul insists that even if an Angel from Heaven preached to you,
reject them!
Paul preached his Gospel was truly unique as it was delivered to
him by Jesus himself; not Jesus the earthly man, but the risen
Lord Jesus.
According to Paul, he had the advantage of divine origin for his
message, unlike the other Apostles, and this entitled him to act
independently of their Jewish-Christian beliefs (and re-invent a
new Christian doctrine?)