Indeed he was ill, and almost died. But God had mercy on him, and not on him only but also on me, to spare me sorrow upon sorrow.
Philippians 2:27, NIV

What was Paul’s opinion of the majority of Christian workers?
They were seeking their own interests, their own aims, their own goals, not those of the Lord Jesus. It probably is true that most Christian work throughout history has proceeded apart from the cross, apart from the leading of Christ. apart from the guidance of the Holy Spirit. This may appear to be too sweeping an indictment, but it is what Paul is saying. Denominational barriers exist, not because Jesus Christ is setting saint against saint but because men are seeking to gain fruitfulness and dominion apart from union with Jesus Christ. It is not possible that the one head, Jesus, would encourage one part of His Body to attempt to draw members away from another part of His Body. Therefore, we know that many Christian leaders are walking and serving according to their fleshly ambitions.
The Cross reconciles all believers. The Cross causes dependence on the power of Jesus Christ. The Cross removes King Self from the throne of our heart and installs King Jesus for eternity. No doubt it is true that during the spiritual darkness that even now is filling the earth, the believers in Jesus Christ will be divided into two camps; those who are filled with Christ, and those who claim to be Christians but are not filled with is life. As soon as this separation and the fruit of it have become mature, the Lord Jesus will return. Then the “synagogue of Satan” will understand that Jesus Christ loves His true, Cross-Carrying Saints. Then the righteous will shine in the Kingdom of their Father the Lord Jesus.