Charles Mchatton preaches about how God refines and chooses His children in the furnace of affliction, using trials, oppression, and humiliating experiences to purify their hearts and prepare them for higher ministry. Just like how automobiles are tested before being put on the market, God tests His children to reveal weaknesses and refine them. Through the examples of Moses, Joseph, and the three Hebrew children, it is evident that God chooses and refines His workers in times of distress and difficulty, enlarging them for effective ministry when they remain faithful in the midst of trials.