Charles Spurgeon once preached a sermon entitled “The Bellows Burned” (September 12, 1869). Bellows were used to heat up the fire in a furnace so as to extract the pure metal from the dross. In this case, the bellows melted before this could be done. Jeremiah likened himself to the bellows who, in his preaching, was trying to remove the hardness from their hearts. He exhausted himself before the people repented. He described himself with these words: “The bellows are burned” (Jeremiah 6.29).
In this sermon, Spurgeon described supposed conversions apart from repentance. He said, “I have known, in my short time, certain churches, in the paroxysms of delirium, meeting houses crowded, aisles filled, preachers stamping and thundering, hearers intoxicated with excitement, and persons converted by wholesale - even children converted by hundreds - they said thousands. Well, and a month or two after, where were the congregations? Where were the converts? Echo has answered, ‘Where? Where?’ Why, the converts were worse sinners than they were before; or mere professors, puffed up into a superficial religion, from which they soon fell into a hopeless coldness, which has rendered it difficult ever to stir them again.”
He mentioned “intoxicated with excitement.” Talk about an emotional high! This is clearly describing “zeal without knowledge” (Romans 10.2). This is why emotions cannot be a standard whereby we can judge true conversion. It points to the need for “sound doctrine” (Titus 1.9; 2.1). A lie, when believed, has the same emotional effect as does truth (Genesis 37.33-35). Only sound doctrine can bring about genuine repentance and conversion. The same answer that the Lord gave his apostles on repentance and conversion must be given today. This is why the Lord warned: “Take heed what and how ye hear” (Mark 4.24; Luke 8.18). Remember, doctrine matters!