Hebrews 12:14-16

Follow peace with all men, and holiness, without which no man shall see the Lord: looking diligently lest any man fail of the grace of God; lest any root of bitterness springing up trouble you, and thereby many be defiled; lest there be any fornicator, or profane person, as Esau, who for one morsel of meat sold his birthright.
Hebrews 12:14-16