Deuteronomy 29:18
Beware lest there be among you a man or woman or clan or tribe whose heart is turning away today from the LORD our God to go and serve the gods of those nations. Beware lest there be among you a root bearing poisonous and bitter fruit,
Hebrews 12:15
See to it that no one fails to obtain the grace of God; that no "root of bitterness" springs up and causes trouble, and by it many become defiled;
Deuteronomy 11:16-17
Take care lest your heart be deceived, and you turn aside and serve other gods and worship them;
Deuteronomy 13:1-15
"If a prophet or a dreamer of dreams arises among you and gives you a sign or a wonder,
Deuteronomy 17:2-7
"If there is found among you, within any of your towns that the LORD your God is giving you, a man or woman who does what is evil in the sight of the LORD your God, in transgressing his covenant,
Jeremiah 9:15
Therefore thus says the LORD of hosts, the God of Israel: Behold, I will feed this people with bitter food, and give them poisonous water to drink.
Hosea 10:4
They utter mere words; with empty oaths they make covenants; so judgment springs up like poisonous weeds in the furrows of the field.
Amos 6:12
Do horses run on rocks? Does one plow there with oxen? But you have turned justice into poison and the fruit of righteousness into wormwood--
Acts 8:23
For I see that you are in the gall of bitterness and in the bond of iniquity."
Hebrews 3:12
Take care, brothers, lest there be in any of you an evil, unbelieving heart, leading you to fall away from the living God.