It is easy to be duped into thinking that just a little error is harmless and will not matter. And yet Scripture teaches otherwise. Pastor and author Joshua Harris speaks of “half a poison pill” to describe the mindset of many Christians in which they think repeated exposure to just a little bit of evil will not harm them. These Christians seem to think they have a sin threshold beyond which they dare not go. Yet these people may as well ask just how much of a poison pill they need to swallow before it kills them. “The greatest danger of the popular media is not a one-time exposure to a particular instance of sin (as serious as that can be). It’s how long-term exposure to worldliness—little chunks of poison pill, day after day, week after week—can deaden our hearts to the ugliness of sin. Repeated exposure to error can lead us to unwittingly swallow a lethal dose. Error may be subtle but it is always deadly.
The truth is under attack more today than at any other time in history and this should not be surprising in a culture that so values religious freedom and tolerance. Add to such an accepting culture unparalleled speed of communication and the ability to publish books and other writings quickly and easily, and we can rightly conclude that error is being spread with startling speed and efficiency. What the church needs today is a class of believers who are identified as the experts in discernment and as those who have special ability in this area.–Tim Challies, The Discipline of Spiritual Discernment