Paul’s gospel is simply believing on Christ’s death, burial, and resurrection.

1 Corinthians 15:1-4, “Anyone who adds to this gospel must be damned, even if it is angel from heaven.”

Galatians 1:8 reads, “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.”

This brings up a problem in Revelation 14, 6a-7a which reads, “And I saw another angel fly in the midst of Heaven, having the everlasting gospel. Saying with a loud voice, ‘Fear God, and give glory to Him; for the hour of His judgment has come and worship him.”

Weren’t there times we Christians were guilty of not fearing God? Or worshiping God?

That’s clearly different from simply believing in Christ’s death, burial, and resurrection.

The answer is that the gospel in Revelation 14 is for tribulation saints, not Christians.

Christians with Paul’s gospel are not in the tribulation so there’s no contradiction. Insisting otherwise makes the Bible verses contradict each other.