A good Bible student often incorporates many of the same tactics as a good detective. Defining Bible words involves such a task. No single verse specifically defines the word bitterness. Yet, a careful study of a few verses will help to bring the pieces together and to provide understanding. According to Isaiah, bitterness and peace are at opposite ends of the emotional spectrum (Isaiah 38:17). Proverbs associates the word bitter directly to the word sharp (Proverbs 5:4). And, lastly, the word bitter is connected to the word affliction (2 Kings 14:26, Lamentations 1:4). Using these scriptural clues, a good student will understand bitterness to be a sharp affliction. Additionally, consider the connection between the words bitter and bite, making bitterness a sharp affliction with bite. Bitterness always begins on the inside of an individual and, as we will learn, eventually works its way to the outside for others to see.
Believers should seek to be pure in every facet of life. One might consider limiting this to the places he goes or the things he hears and sees, but purity demands a much greater focus. Believers ought to think on pure things (Philippians 4:8) with pure minds (2 Peter 3:1) and pure consciences (1 Timothy 3:9; 2 Timothy 1:3). In particular, believers should have pure hearts before the Lord (1 Timothy 1:5; 2 Timothy 2:22). A pure heart will lead to a pure conscience and a pure mind. A pure heart changes where a man goes, what he looks upon, and the things he allows to enter into his ears. Every Christian should strive to make sure that all things are pure.
