Verses with the word bitter in the New Testament (6 verses):

Colossians 3:19
Husbands, love your wives, and be not bitter against them.

James 3:11
Doth a fountain send forth at the same place sweet water and bitter?

James 3:14
But if ye have bitter envying and strife in your hearts, glory not, and lie not against the truth.

Revelation 8:11
And the name of the star is called Wormwood: and the third part of the waters became wormwood; and many men died of the waters, because they were made bitter.

Revelation 10:9
And I went unto the angel, and said unto him, Give me the little book. And he said unto me, Take it, and eat it up; and it shall make thy belly bitter, but it shall be in thy mouth sweet as honey.

Revelation 10:10
And I took the little book out of the angel's hand, and ate it up; and it was in my mouth sweet as honey: and as soon as I had eaten it, my belly was bitter.