Isaiah 58:1

Matthew 3:7-9 NIV
But when he saw many of the Pharisees and Sadducees coming to where he was baptizing, he said to them: “You brood of vipers! Who warned you to flee from the coming wrath? Produce fruit in keeping with repentance. And do not think you can say to yourselves, ‘We have Abraham as our father.’ I tell you that out of these stones God can raise up children for Abraham.

Titus 2:15 NIV
These, then, are the things you should teach. Encourage and rebuke with all authority. Do not let anyone despise you.