The word gospel derives from the Old English gōd-spell, meaning “good news” or “glad tidings”, and is a word-for-word translation of the Greek word euangelion meaning good message. While gospel is a good news, it can mean different for different people. Similarly, the gospel preached by Christ is very different from what Paul referred as gospel.
Acts 20:24 “But none of these things move me; nor do I count my life dear to myself, so that I may finish my race with joy, and the ministry which I received from the Lord Jesus, to testify to the gospel of the grace of God.
Gal 1:6-7 I marvel that you are turning away so soon from Him who called you in the grace of Christ, to a different gospel, which is not another; but there are some who trouble you and want to pervert the gospel of Christ.
The gospel preached by Paul is grace of God. We see this repeatedly in his letters.
Eph 2:8-9 For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast.
In Paul’s version of gospel, the grace of God will save us through faith and we cannot do anything to be saved. Therefore, it is a good news to him.
Mark 1:14-15 Now after John was put in prison, Jesus came to Galilee, preaching the gospel of the kingdom of God, and saying, “The time is fulfilled, and the kingdom of God is at hand. Repent, and believe in the gospel.”
Rev 14:6 Then I saw another angel flying in the midst of heaven, having the everlasting gospel to preach to those who dwell on the earth–to every nation, tribe, tongue, and people– saying with a loud voice, “Fear God and give glory to Him, for the hour of His judgment has come; and worship Him who made heaven and earth, the sea and springs of water.”
The gospel preached by Christ is about His Kingdom and the coming Judgment. Jesus never preached salvation by grace anywhere.
Mark 8:34-35 When He had called the people to Himself, with His disciples also, He said to them, “Whoever desires to come after Me, let him deny himself, and take up his cross, and follow Me. For whoever desires to save his life will lose it, but whoever loses his life for My sake and the gospel’s will save it.
In Christ’s version of gospel, you need to deny yourself and lose your life for Christ’s sake and gospel’s sake to save your life.
The gospel preached by Paul is not the same gospel preached by Christ. You have two choices. The popular choice is a wide gate and broad way, where you are saved by God’s grace through faith and nothing is required of you but leads to death, which is the gospel of grace by Paul the Pharisee. The unpopular choice is a narrow gate and difficult path where you had to deny yourself to live holy and righteous that leads to life, which is the gospel of the kingdom of God preached by Jesus Christ. The choice is up to you. Repent, and believe in the gospel of Jesus Christ, not Paul.