to equip the saints for the work of ministry, for building up the body of Christ,  until we all attain to the unity of the faith and of the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ,  so that we may no longer be children, tossed to and fro by the waves and carried about by every wind of doctrine, by human cunning, by craftiness in deceitful schemes. (ESV)
So, after Paul has described the essential gifts of leadership to the church (Apostles, Prophets, Evangelists, and Pastor-Teachers), he describes the ultimate goal of following these leaders. Listen to some of these key words: unity, knowledge, maturity. It is amazing to me that some 2000 years later these continue to be great needs in the church. And the main reason why unity, knowledge, and maturity are lacking is that we have not heeded the leadership that God has given to his church.
The teaching that we gain from the words of the Apostles and Prophets are essential truth for us. The Evangelists preach the Gospel and bring people into the church. The Pastor-Teachers give them further instruction. What is the result? People become unified as they all are committed to the same message of the Gospel. Their knowledge is increased as they hear the whole counsel of the Word of God preached and taught. And ultimately, they become mature, and unwavering. They are the pillars of the faith that cannot be swayed by the false doctrine and cunning of the enemy.
The need in the first century church is the same need that we have today. I have talked with so many Christians that believe such nonsense. They are swept away by the latest "Christian fad." They have even incorporated occultic practices into their lives. They fight for their own way in church meetings, displaying a complete lack of maturity. How sad. But, there is hope. It is always found in God's Word. Paul's instruction for us is clear.
Do you want to be mature in your faith, acting in unity, and growing in the knowledge of the Son of God? Devote yourself to the teaching of the Apostles and Prophets. Support the work of Evangelists and Preacher-Teachers. Let's grow up together!