"Now these (the Bereans) were more noble-minded than those in Thessalonica, for they received the word with great eagerness, examining the Scriptures daily to see whether these things were so." (Acts 17:11, NASB)The intention of the above verse was not to justify skeptical scrutiny of ministers with whom we disagree. There are other passages in Scripture that warn us to be on our guard of false prophets or false teachers, but the context of this verse in Acts 17 is not related to exposing false teaching.
Paul & Silas have just traveled from Thessalonica, where they preached Christ and had some measure of success in persuading some Jews, Greeks and "prominent women" to accept their message. However, the Thessalonian Jews stirred up a mob to try to discredit Paul & Silas. They went so far as to falsely accuse Jason and some other believers of inciting political trouble in the name of Jesus.
That night, Paul & Silas sneaked out of town and headed to Berea, where the message of Christ was received "with great eagerness." Consider verse 13:
When the Jews in Thessalonica learned that Paul was preaching the word of God at Berea, they went there too, agitating the crowds and stirring them up. (Acts 17:13, NIV)There was a big difference between the Jews in Thessalonica and the Bereans. The Jews in Thessalonica were trouble-makers. They made accusations against legitimate spiritual leaders with no basis in fact. They went out of their way to attempt to discredit and silence God's chosen leaders.
The Bereans had a much different attitude. They were eager to receive the message of Christ that Paul brought. Their foundation was hearts that were open, teachable, and receptive to the truth. They wisely compared the teaching with Scripture and found that it was correct and true.
Of course, there is a third city discussed at length in Acts 17. Athens was characterized by its obsession with knowledge. Visitors to Athens could add their favorite religious beliefs to the smörgåsbord of Athenian philosophy. Then heap their epistemic plate with a scoop of whichever beliefs appealed to their spiritual palates. Athens is the city that most people come from today: "Yes, I'd like to sample that spiritual dish. No thank you, that doesn't appeal to my taste. I'll leave that on the buffet for someone else." They must be reached through creative methods such as the contextualized approach used by Paul on Mars Hill.
But there are others today who come from Thessalonica. They cause trouble, point fingers, spread false accusations. They even travel to other towns to expose and discredit spiritual leaders that they consider to be heretical, using modern methods of virtual travel such as the internet and email to get their message out. They spend their time trying to stir up mobs to agree with them. Their hearts are hard and they are consumed with their anger, self-righteousness, and insecurity.
Thankfully, there are still some Bereans around. There are people who actually study Scripture because they are eager to know the truth. They're not looking for stones to throw. Their fingers trace across lines of Scripture text rather than pointing at those with whom they disagree. Their noses are buried in The Book and waste little time sniffing out false teaching. They are trusting, meek, and their hearts are still soft and pliable. Find these people. They have a tendency to rub off on you and make you all Christ-like.
What percentage of our time does God want us to spend on rooting out heresy or exposing false prophets? I mean, we're supposed to: go into all the world and preach the Gospel; care for the needs of widows and orphans; pray continually; allow God to work miracles through us; use the gifts of the Spirit that God has uniquely placed within each of us; study God's Word to show ourselves as approved workers; always be prepared to give an answer (in love) to anyone who asks us about our faith; do spiritual warfare; resist the devil; flee from temptation; "hide" God's Word in our heart (memorize Scripture); use Scripture to encourage, rebuke, correct, & train others; live in unity with other believers--just to name a few. Those things all take a lot of time. How would God prioritize these activities?