'Bitter' in the Bible

See to it that no one comes short of the grace of God, that no one be like a bitter root springing up and causing trouble, and through him many become defiled.

A spring does not pour out fresh water and bitter water from the same opening, does it?

But if you have bitter jealousy and selfishness in your hearts, do not boast and tell lies against the truth.

So I went to the angel and asked him to give me the little scroll. He said to me, "Take the scroll and eat it. It will make your stomach bitter, but it will be as sweet as honey in your mouth."

So I took the little scroll from the angel's hand and ate it, and it did taste as sweet as honey in my mouth, but when I had eaten it, my stomach became bitter.