But when [John] saw many of the Pharisees and Sadducees coming for baptism, he said to them, "You brood of vipers! Who warned you to flee from the wrath to come? Bear fruit that befits repentance; and do not presume to say to yourselves, 'We have Abraham as our father;' for I tell you, God is able to raise up children to Abraham from these stones. Even now the ax is laid to the root of the trees; every tree that does not bear good fruit is cut down and thrown into the fire.
"I baptize you with water for repentance, but he who is coming after me is mightier than I, whose sandals I am not worthy to carry; he will baptize you with the Holy Spirit and with fire. His winnowing fork is in his hand; and he will clear his threshing floor and gather his wheat into the granary; but the chaff he will burn with unquenchable fire."