God only gave "some" (Eph 4:11) five-fold gifts. How does a person know he has one of those gifts? Jesus told Ananias that Paul was "'a chosen instrument of Mine'" (Ac 9:15). I was taking some Bible courses on-line from a school, and the instruction in one course was that their denomination wouldn't recognize anyone being in the ministry until they had earned a degree, which assumes that they had followed through to get their credentials. According to this denomination in Paul's case it wouldn't matter if "the stewardship of God's grace . . . was given me" (Eph 3:2), or "the stewardship from God [was] bestowed on me" (Col 1:25), or "I was appointed a preacher" (2Ti 1:11) and "this grace was given to preach" (Eph 3:8), since his statement that he "was made a minister" (:7) on its own wouldn't have been recognized by the denomination.
God gave apostles, prophets, evangelists, pastors and teachers "for the equipping of the saints for the work of service" (Eph 4:12). Some say the first two have fulfilled their purpose in founding the church and these people are called cessationists. Nonetheless, anyone in these five categories would have the qualification to train the saints. But does that mean that you couldn't understand anything yourself by studying the Bible on your own? I've heard some pastors say to their congregations that it was their exclusive responsibility to provide Bible instruction. In one church I attended it was made clear that only the pastor could officially counsel the flock. One day I saw an attendee downtown and bought him a cup of coffee and piece of pie and shot a game of pool with him. He was mentally challenged and should have made an appointment with the pastor. One day he saw me driving down the street and almost ran in front of the car. Unfortunately a month or so later he jumped off a bridge downtown into a waterfall and killed himself. Its like the veterans who died while waiting for their VA hospital appointments. In one sermon that church's pastor quoted a scripture saying that anyone who didn't cooperate with his recommendations would be disobedient. I operated the bookstore and checked out a great number of tapes on that sermon and soon almost half the church left. Much later I told the pastor what those people had concluded and he replied he hadn't said anything wrong. Then he died and the next pastor was requiring potential members to sign a document promising to follow his leadership. Many church splits are caused by so-called leaders trying to control the "laypeople." Once I visited churches in a nearby town and their overseers had created a document for potential members to sign promising to seek counseling before jumping to another church.
The "work of service, [is] to the building up of the body of Christ; until we all attain to the unity of the faith, and of the knowledge of the Son of God, to a mature man, to the measure of the stature which belongs to the fullness of Christ" (Eph 4:12-13). "We are to grow up in all aspects into Him" (:15) as a body that "grows with a growth which is from God" (Col 2:19). It is for "building up" (Eph 4:12) so that "the whole building, [is] being fitted together [and] is growing into a holy temple in the Lord" (2:21) "into a dwelling of God in the Spirit" (:22).