Others Using

One verse that hurts the Mutual Edification concept is 

I Corinthians 9:12

"If others share this rightful claim on you, do not we even more." ESV

Notice the plural. There was already a plural number of people receiving money from the Corinthian church. It doesn't say who; Perhaps elders, perhaps Apollos, perhaps other evangelists. It is clear they were supporting multiple people. It is possible some were local teachers which they clearly had. Apollos was previously watering in ch.3. After Paul left he went to Corinth.

The theory a group of churches select one evangelist among them all, and that is who gets paid, is debunked. It wasn't the only pattern possible. Corinth supported more than one. Plus Paul and Barnabbas could make the same claim for support if they chose to ask. That would make 4 minimum, plus the other Apostles mentioned and the Lord's brothers.

Paul was simply answering those who said Paul was inferior for not accepting their money, or wrong for accepting money from other churches, which he did. Paul in defending himself from either complaint was clear to defend the practice itself.

Sometimes they say they must be "proclaiming" Christ and not teaching, but at the Lord's Supper we "proclaim" the Lord's death. The idea you proclaim outside the church and not inside the church is silly beyond belief. We proclaim to visitors and members different aspects of the Gospel each Sunday.

One good study is Colossians and Philemon. Colosse had a preacher named Epaphras whom they heard the word from Col.1-7, currently he was with Paul and Timothy in the same place. Imagine 3 men in the same town all getting support from somewhere. Then in the last chapter Tychicus is sent to Colosse to comfort the body Col.4:7, and Archippus receives a ministry from the Lord in Colosse Col. 4:17. You see two men in ministry there now.

Philemon says the church met in his house. Here is a man in ministry who probably doesnt travel abroad because the church is in his home. Perhaps he is an Elder, perhaps an evangelist, perhaps just a ministry of some sort. You have an evangelist replacing a different evangelist with another put in ministry. They likely could have more than one in a teaching ministry. If one was an elder and one a preacher, then you have an evangelist comforting a church with elders. Or you have two ministers concurrent.

Both probably had different missions. You can have two men in ministry with different missions as given to them by an Apostle or by Christ through prophecy.

Having a preacher or two at an established congregation is biblical.