The perfecting ones of this kind of Christian perfection are the gifted persons, such as the apostles, the prophets, the evangelists, and the shepherds and teachers (Eph. 4:11-12).
The apostles define the truths for the establishing of the church. With James there was a shortage of the truth of God's New Testament economy. James did not realize four pairs of things. First, God has two testaments: the Old and the New. Second, God has two parts of His economy: the Old Testament dispensation and the New Testament dispensation. These should not be mixed up. Third, God has two peoples: the Old Testament people, Israel, and the New Testament people, the church. Fourth, a regenerated person has two men: the old man and the new man. James's writing mixed up these four pairs of things. Actually, he needed a proper apostle to define the truths to him, to perfect him.
The prophets prophesy for the building up of the church (1 Cor. 14:3-5). Proper prophets prophesy the divine word, not mainly to predict but mainly to speak forth the Lord. This is what Isaiah did when he spoke concerning a virgin bringing forth a child whose name is the Mighty God and the Eternal Father (9:6).
The evangelists preach the gospel to make sinners the members of Christ for His Body. They preach the gospel not for soul-winning but for Christ's member-winning. They win sinners to make them the members of Christ for His Body, not to gain souls for them to go to heaven.
The shepherds feed the young believers that they may grow up for the building of the Body of Christ (John 21:15-17; Eph. 4:15-16).
The teachers teach the believers for their edification to establish the churches (cf. 1 Tim. 3:2; 5:17).