Salvation Is Only By Abiding In the Everlasting Gospel

The word 'gospel' literally means good news. And, yes, we are saved by the 'Gospel' message. But is that the 'Gospel about Jesus' based on Paul's letters, or is that the 'Gospel given by Jesus'? The Gospel given by Jesus is the 'Everlasting Gospel' which we read in the Book of the Revelation 14:7. There are two distinct and contrary 'gospel' messages in the New Testament. These gospel messages are so contrary that they are mutually exclusive, we have to pick one or the other.
Why are there sharp contrasts between the two Gospel messages? Why are they mutually exclusive? Which one is the true gospel that will save us? That's what we will examine in this book.