"Watch out for false prophets. They come to you in sheep's clothing, but inwardly they are ferocious wolves. (Matthew 7:15 NIV)
Ironically, though, we are not told to listen to their teaching to compare it to Scripture. Instead, Scripture tells us to look at their lives to see if they are good.
By their fruit you will recognize them. Do people pick grapes from thornbushes, or figs from thistles? Likewise, every good tree bears good fruit, but a bad tree bears bad fruit. A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit. (Matthew 7:16-18 NIV)
We shouldn't be listening to to their teaching before we look at their lives. Before we trust people to lead us, its important to see if they are walking together with God themselves. Otherwise, we could find ourselves following someone down the wrong path. That could be quite bad.
Every tree that does not bear good fruit is cut down and thrown into the fire. Thus, by their fruit you will recognize them. (Matthew 7:19-20 NIV)
So, how about you? What do you look for in a preacher, teacher, or leader in the Church? Do you follow people whose lives reflect a walk together with God?