There is a common assumption that there is only one Gospel message in the Bible. This is a misconception. We can avoid it by understanding there are at least two basic Gospel messages in the Bible. While there is only one Gospel message today, God did not reveal the grace gospel for today until the Apostle Paul received it from the Ascended Lord Jesus. God has had other Gospel messages valid at other times in human history.
We read in Matthew chapter 16:13-23.