Why does beatty want montag to wield the flame thrower to destroy his own house and why does montag acquiesce

Not sure if this will help you...but this is what I found:

The title of the third section, "Burning Bright", references the many allusions to fire and burning in the text. First, Montag burns his home and his possessions. Ironically, Montag does not grieve the loss of his home or possessions. In contrast, he feels unburdened by releasing himself from the intrusive television walls that plagued his life. Thus, Montag's flamethrower dispenses powers of destruction and of cleansing. Before ordering him to burn down his own house, Beatty baits Montag, comparing him as Icarus and thus alluding that Montag, by harboring books, has flown too close to the sun and shall now fall to his death. With this analogy, Beatty argues that those who defy the law of the land will meet their end. Ironically, Beatty is actually the man that dies, while Montag escapes and begins a new life.