This has nothing to do with KJV-only thread as you are implying. Just noticed, that sometimes you used KJV where it seems it fits your theology but withdraws from it when it says something against your theology. Luke for the record says of Paul's manner of reasoning is out of scriptures. Question: are you really reasoning out of the scriptures? You know, I have no problem with the preaching of the gospel but somehow you do have a problem with Paul's preaching to believers. That's somehow it's forcing your belief system against what the Holy Spirit inspiration as writer Luke have written.
I'm not implying anything about KJV only. I haven't read that thread. I don't believe the canon of scripture was open until 1611. Do you? I use the KJV if I don't feel like putting in the extra effort to cite another translation since you don't have to cite KJV. Sometimes I'll use NKJV. I would avoid KJV if I've done a word study and I think the verse is not well translated, and I might avoid another translation if that is the case.
My point in bringing this up is a lot of people think that you are supposed to go to church and hear one man called 'the pastor' or 'the preacher' 'preach' a sermon, a long talk that lasts about 45 minutes. So they use the odd use of the word 'preach' in Acts 20:9 as evidence for this. Really, the word is teach or discourse. Paul could have been leading a discussion, or he could have been teaching.
Most verses about 'preaching' are about evangelism. The words translated 'preach' either refer to this type of evangelistic proclamation, or appear in contexts where they could mean this but aren't conclusive, as far as I've seen. Acts 20:9 in the KJV is an outlier. We should expect it to say 'teach' or dispute or something along those line like other translations render the word.
Paul did not say go to church and hear one person give a long discourse. He wrote, "Every one of you hath a psalm, hath a doctrine, hath a tongue, hath a revelation, hath an interpretation. Let all things be done unto edifying." Paul's instructions are for a church meeting where regular members of the body of Christ speak, using their gifts to edify one another. And this is the only long set of instructions we have on what to do in church, except for chapter 11, which tells how NOT to have the Lord's Supper.
There are other verses, like Hebrews 10:24-25, which say to provoke one another to love and to good works, not to forsake assembling, but to exhort one another. Notice it says exhort one another, not sit down quietly and listen to the sermon.
'Let everything be done decently and in order' is about the Lord's order, regarding the type of meeting described in the passage where prophets can prophesy, but should yield the floor to another sitting by who receives a revelation, where ye may all prophesy, and where speaking in tongues and interpretation is allowed to operate in the proper order described in the passage. We should not read in the pulpit-pew, Sunday sermon concept into this verse about order.
And there are people who think that God chose the foolishness of listening to a sermon week after week for the rest of your life to save them that believe, as opposed to thinking that God chose the foolishness of hearing the evangelistic preaching of the Gospel to save them that believe.