Why can't I mix Jewish ministries with Paul's ministry to the Gentiles?
They cannot be mixed because Scripture assigns distinct roles: Jesus and Peter with the eleven served Israel, while Paul was the apostle of the Gentiles. Each ministry must remain exactly where it is; combining them produces confusion rather than sense. Paul's Gentile doctrine is that all were dead until Christ's life-giving power through faith in the Gospel.
Les explains that there is perfect understanding that you cannot mix all these things together and make sense out of it, but it all has to be left exactly where it is. Jesus dealt with the Jew; Peter and the eleven were the apostles of the Jew; Paul then comes on the scene as the apostle of the Gentiles. In 2 Corinthians 5, Paul writes to the Corinthians, who were Gentiles. Paul says the love of Christ constraineth, or drives, us because we conclude that if one died for all, then we are all dead. That is Paul's doctrine: we were dead in our trespasses and sins, and the whole human race is dead until Christ moves in with His life-giving power, which is triggered by faith in the Gospel.