Several years ago a cultural anthropologist went to American Samoa to revisit old women the "great" Margaret Mead interviewed when they were teens which led to her famous work Coming Of Age In Samoa, in which she provided "support" for her goal of broadening sexual mores. Much to his surprise (since he was a Mead admirer) the aged Samoan women admitted that when they were girls they lied and invented fantasy stories for Mead because they (correctly in my opinion) discerned that she wanted to hear lurid details of their sexual exploits. Thus, cultural anthropology for the later half of the 20th century was built on adolescent fantasies.
Java Man (Homo erectus erectus) is the name given to fossils discovered in 1891 on the island of Java. Years passed before the "discoverer" admitted that the skullcap, femur, and a few teeth he unearthed were obtained at different locations and different depths of a large dig site and could not have been from the same individual or the same species. Thus, paleontology for more than half a century was (and I believe still is) built on error.
The same kind of professional coverup has occurred within the ranks of the gospel ministry. About two centuries ago, pastors routinely interviewed inquirers and hopeful converts in an attempt to discern their spiritual condition and the accuracy of their understanding of important spiritual truths vital to their eternal well-being. Though the term is trivialized from overuse, a paradigm shift really did occur when Charles G. Finney succeeded in discouraging many ministers from proceeding cautiously and carefully with inquirers and hopeful converts, and insisted on immediately pronouncing to be saved anyone who claimed to have trusted Jesus. This despite the warning from Jesus in the parable of the soils (Mt 13.20-21) that even those not truly converted will initially seem to joyfully respond to the gospel. Since the first half of the 19th century most ministers have abandoned the practice of personally interviewing individuals carefully to discern their grasp of the truth (London pastor Charles Spurgeon being a notable exception to the trend).
The nasty truth? Few men who seem successful as indicated by the numerical growth of their churches have any interest in pursuing a line of inquiry that might reveal the true condition of a tithing regular attender who presently causes no trouble for the pastor. That would rock the boat. Yet the principle is well established in the Bible that important matters are to be subjected to two or three witnesses to establish certainty (Deut.7.17; 19.15; Matt. 18.16, 19). Even the Lord Jesus Christ and God the Father hold themselves to that standard (Luke 7.19-22; First John 5.7-8).
Preachers of the gospel need to return to the Biblical principle of feedback, interviewing their auditors much in the same way doctors obtain case histories and investigators interview witnesses. How else will preachers discover what their audience thought they declared? How else will they learn what their hearers seem to grasp of the truth which is declared? How else are Baptist preachers to learn who among those who desire to be baptized are actually qualified for believer baptism?
Understand that I make no claim that any pastor decides who is and is not saved, or which sinner is or is not serious about his spiritual condition. I only urge men of God to seek to discover the condition of those they have been given watch care over, rather than presuming that everyone who claims to be a Christian actually is a Christian. Are such attempts at discernment warranted? Of course they are. Are not marriages supposed to be among Christians? Are not partnerships supposed to be limited to believers? Such is commanded in God's Word. Is not baptism restricted to believers? Therefore, the insistence that such things cannot be ascertained is not valid, even though we recognize that 100% accuracy in such matters is unobtainable.
Feedback is a principle that exists in nature, is sought in business, in engineering, in law, in medicine, by the military, and is required according to scripture when dealing with important matters of fact. I submit that ministers of the gospel are compelled to seek feedback from those they minister to by both scriptural principle and the necessities of common sense.