Acts 8:23
"For I perceive that you still stand in the gall of bitterness and in the bondage of unrighteousness."
Romans 1:31
They were without sense, without faith, without natural affection, without mercy.
2 Timothy 3:3
without natural affection, merciless, slanderous, dissolute, and brutal.
Hebrews 12:15
Look carefully that there be no one who falls back from the grace of God; that no root of bitterness springs up to trouble you, and by its means many become defiled.
Revelation 8:10-11
And the third angel blew his trumpet, and there fell from heaven a great star, blazing like a torch. It fell upon a third of the rivers and upon the springs. (The name of the star is called Wormwood.)