I think that the best way to understand Ephesians 4:12 is to remove the commas: “For the equipping of the saints for the work of ministry for the edifying of the body of Christ.” This verse is saying that the job of a pastor-teacher is to equip the saints to do the work of the ministry and as a result, the church will grow. This is how Christ builds His church. But what resources does the pastor-teacher have to accomplish this? In 2 Timothy 3:16-4:2, the Apostle Paul tells us.
All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, 17 that the man of God may be complete, thoroughly equipped for every good work. 4:1 I charge you therefore before God and the Lord Jesus Christ, who will judge the living and the dead at His appearing and His kingdom: 2 Preach the word! Be ready in season and out of season. Convince, rebuke, exhort, with all longsuffering and teaching.
John MacArthur has correctly drawn attention to the link between a belief in the inspiration and inerrancy of Scripture and the need to preach it expositionally.
The only logical response to inerrant Scripture, then, is to preach it expositionally. By expositionally, I mean preaching in such a way that the meaning of the Bible passage is presented entirely and exactly as it was intended by God.
This is why whenever a church chooses a pastor, it should be a non-negotiable that the man be an expository preacher. Not everyone who claims to preach expositionally, actually does it. There may be some who don’t know the word, but do preach expositionally. Expositional preaching is preaching that takes as the point of the message, the point of the passage being preached. It’s not a special ability or a style, it is the pastor-teacher’s calling! It’s simply preaching the meaning of a text. Very simple, but it takes hard work to know the meaning of the text and communicate it to God’s people.
To put it another way, expositional preaching, as I once heard Danny Akin say, does not view a text as a peg to hang a bag of miscellaneous thoughts, but as a master that determines what is said. The calling of a pastor-teacher is to equip the saints by the proclamation of the Word of God just as the Holy Spirit of God inspired it. It’s interesting that those who talk so much of the Spirit of God, prefer a method of preaching which basically says that the Holy Spirit did not do a good job organizing Scripture. Instead, they seem to think, they can do a better job.