Charles Spurgeon Commentary Matthew 3:10-12

"And even now the axe lieth at the root of the trees: every tree therefore that bringeth not forth good fruit is hewn down, and cast into the fire. I indeed baptize you in water unto repentance: but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you in the Holy Spirit and [in] fire: whose fan is in his hand, and he will thoroughly cleanse his threshing-floor; and he will gather his wheat into the garner, but the chaff he will burn up with unquenchable fire." — Matthew 3:10-12 (ASV)

And now also the axe is laid unto the root of the trees: therefore every tree which bringeth not forth good fruit is hewn down, and cast into the fire. I indeed baptize you with water unto repentance: but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shalt baptize you with the holy Ghost, and with fire: whose fan is in his hand, and he will throughly purge his floor, and gather his wheat into the garner; but he wilt burn up the chaff with unquenchable fire.

The Christ is the minister of mercy, but there is about his doctrine a searching and a trying power. Only the sincere in heart can endure Christ's winnowing fan. As for the insincere, they are blown away like the chaff on the threshing-floor, and their end is destruction. God gave us to be numbered amongst the wheat that Christ shall gather into his heavenly garner!