The Gospel of Jesus Christ states Jesus Who is God came in the form of man to save all men from their sin, providing justification of righteousness for all who place their faith in Him.
From the cross, Jesus declared, “It is finished!” This means ALL the work of salvation has been accomplished in Him. All the work necessary for the salvation of mankind has been completed. There is nothing which can be added to the finished work of Jesus Christ. Any attempt to do so takes away from His work on the cross, declaring it to be less than effective for salvation. To add anything to the finished work of Jesus Christ on the cross is a perversion of the Gospel of Jesus Christ.
Sometimes, men we perceive to be of greater religious or spiritual stature – or even those we may perceive to be an angel – come along and declare a different Gospel or add to the Gospel Jesus Himself declared. Of these men – or even of angels – Paul said, “Let them be accursed!”
Of all people, Paul was sensitive to the message of the grace of God, which is encapsulated completely in the finished work of the cross. To introduce anything to the work of the cross is to introduce the uncertainty of human performance. This must remain anathema to all Bible-believing Christians. To attempt to earn something freely provided by God in the sacrifice of His Son is to denigrate the effectiveness of that sacrifice.
Paul understood for grace to be grace, it must remain grace. The instant it becomes less than grace it becomes ineffective for salvation.
For this reason, the Judaizers who have come to the church at Antioch, Syria are especially troubling to Paul and Barnabas. These Judaizers have come from Jerusalem, and we may suppose they had impressive credentials since they were from the home of the ‘mother church.’ But they came with no credential at all. They were taking things upon themselves and could have overturned the Gospel of grace had they been successful.
Paul would personally see to it this could not be allowed to happen. Of all his mission trips, this may have been his most important.