Most of this letter was to rebuke and correct the wrong teaching and practice in the church at Corinth. They had been spiritually side-tracked, as demonstrated by their wrong behaviour. So Paul concluded the letter by encouraging them to refocus on the true gospel about Jesus, His death and resurrection. The faith of the church can never rest on Christian morals and doing good (Ephesians 2:8-9). It must rest on Jesus who died to pay for the punishment our sins deserve, and who was raised to make us right with God (Romans 4:25). Nothing should matter more to sinful human beings: and there is no better message to announce to a corrupted world (Acts 4:12).
 
The gospel was not invented by anyone. It was received by the apostles directly from the Lord. Paul's experience was unusual and dramatic, but no less valid (Galatians 1:11-20). It was not Paul's gospel but Jesus' gospel: the people in the church had believed what Jesus revealed to the apostles … they were trusting Jesus. Paul's role was to package and deliver the message in ways that different people could understand (1 Corinthians 9:22). When Paul preached, the Holy Spirit enabled people to receive the gospel in repentance and faith, receiving Jesus and being made children of God (John 1:12).
 
The apostolic gospel is the only secure foundation for time and eternity. Some people (like Paul) had been persecuted for believing, but they stood firm on the truth. They were saved for eternity because they trusted in Christ. But some were tempted to follow attractive super-spiritual leaders who offered what their sinful hearts wanted (2 Timothy 4:3-4). Paul said that they could only be assured of salvation by holding firmly to the gospel he preached. If they let go of the apostles' message there was no other route to heaven, and their membership of the church was meaningless acting.
 
Every generation in the church faces the same challenge. Accept the gospel, packaged and delivered by the apostles, or lose assurance of salvation. 'Holding firmly to the Word' is not a Christian option; it is essential for godliness and eternal salvation. Whenever the gospel is changed to make people think that they are saved by good works, religious rites, financial giving, or inventing a new form of personal pietism … its promoters are spiritually dangerous to themselves and their hearers (Galatians 1:9). Protect yourself spiritually by reading God's Word, agreeing with it and asking God's help to do it. There is no other way forward except by standing firm in the grace of Christ (www.crosscheck.org.uk).