If you look at Acts 20:30, you will find that men will arise speaking twisted things and draw away the disciples, presumably from the church in Ephesus (based on context). If that were not concerning enough, these men will come from either the elders with which Paul is speaking or from within the church in Ephesus. But which is it Paul?
It is difficult to tell from Luke's account.
Before peeling back a layer of this less-than-clear sentence, I feel it is worth noting some things about this speech in Acts 20. It's Paul's only recorded speech to believers and it has some remarkable and expected similarities to Paul's letters. But at the time Luke wrote Acts, Paul's letters were not collected and would not likely have been available to Luke. Dr. Witherington sees the numerous parallels between this speech and Paul's Epistles as convincing evidence that Luke recorded this speak from Paul. Likewise, a number of scholars see differences in the writing style of Luke and this speech, which lend to the credibility of the Lukan account and the validity of Luke's witness.
Now, getting back to Acts 20:30.
The ESV translates this verse (in part) as, "and from among your own selves will arise men. . ." The NASB and the KJV do the same. The NRSV says, "even from your own group will come. . ." The NIV84 says, "from your own number" and the Holman says "from your number." The NET Bible translates this, "Even from your own group" with a footnote. (But let's be honest, what's NOT footnoted in the NET translation?)
For those who can read the koine Greek or are curious, here's what it looks like in original language (Textus Receptus, NA27, and UBS4):
καὶ ἐξ ὑμῶν αὐτῶν ἀναστήσονται ἄνδρες λαλοῦντες
The difficult part of the sentence is the word for the plural "you." It's ὑμῶν (humoon). It's like saying "all ya' all" in the South. So Paul's saying from all ya' all, some men will rise up and speak twisted things.
It was probably a little more clear for those who were present. Have you ever been present at a sermon and then listened to it again on a recording? There have been times when I've gestured to my Bible and said something like "This is God's Word." The hearer of the podcast can't see that I'm pointing to my Bible. Or maybe I've walked to different part of the room to make a point? Or maybe there's something in the way I say something that might be lost in the recording, or even more so if it were transcribed.
But before we get lost in translation, we should ask ourselves what the difference could mean.
It is especially alarming if Paul is meaning that from the group of elders he is biding farewell, more than one will rise up, speaking twisted things that draw people away from the church in Ephesus. But is it unreasonable? Have you ever seen an elder of a church speak twisted things and draw disciples away from the biblical church?
But if Paul is referring to someone else who will come, it is still troubling. People within the church at Ephesus will begin speaking false things. Maybe they will start a private meeting. Maybe they will speak behind the back of the leadership. Is this unbelievable? How many bloggers might fall into this group? How many church splits started because of these men, from within the local church?
And at the end of the day, people will be drawn away by false-spoken things. By the time Jesus wrote the letter to the angel of the church in Ephesus (Revelation 2:1-7), the church in Ephesus had already tested people who called themselves apostles and found them to be false. The letter was to those who were not drawn away, so it might be that those calling themselves apostles were the ones speaking twisted things. Maybe the Nicolaitans too.
Paul's warning and charge remain the same regardless if he were referring to someone present at his speech or someone who wasn't. In verse 31-32 he says, "Therefore, be alert, remembering that for three years I did not cease night or day to admonish everyone with tears. And now I commend you to God and to the word of his grace, which is able to build you up and to give you the inheritance among all those who are sanctified" (Acts 20:31-32, ESV).
This problem still exists to this day. Men (and women) rise up and speak twisted things that draw people away from the Church. The way to protect the flock comes from remaining alert, hold tightly to the gospel and admonishing one another to the point of tears, and being built up by the Word of God.