We have been having some great discussions at Bible study about gut feelings; for example, when some say I have a gut feeling about that person, but we have never met that person. I got a gut feeling about the boy my daughter is dating, or I got a gut feeling about the preacher, etc.
We use the phrase "gut feeling" as a synonym for intuition. Intuition is when you have come to a conclusion even though you can't logically explain how you arrived at your conclusion.
The most credible explanation for intuition is found in the pattern matching capabilities of our brains. Our minds are very good at spotting patterns in information. In essence, it is how our minds perceive sights and sounds as objects and words. While men tend to be good at focusing on one concept to the exclusion of all others, women tend to multi-process and deal with a collection of information all at once. Thus women are particularly good at jumping to an intuitive conclusion based on a myriad variety of small clues even though they would be hard-pressed to list each clue out one by one and explain the clue's significance.
A part of this intuitive processing is what we call our conscience. Our conscience is our judgment regarding the rightness or wrongness of a particular course of action.
It can tell us when we are wrong: "Then those who heard it, being convicted by their conscience, went out one by one, beginning with the oldest even to the last. And Jesus was left alone, and the woman standing in the midst" (John 8:9). That is each person might not be able to give you a details explanation as to why it was wrong, but they felt the wrongness deep within them.
The conscience operates on the basis of things we know. "Who show the work of the law written in their hearts, their conscience also bearing witness, and between themselves their thoughts accusing or else excusing them)" (Romans 2:15). But the conscience can be wrong. "Then Paul, looking earnestly at the council, said, "Men and brethren, I have lived in all good conscience before God until this day"" (Acts 23:1). Paul is saying he never offended his inward moral sense of right and wrong. Yet we also know that Paul once persecuted the church. Thus we know that Paul did so out of ignorance. He thought he was doing the right thing, but in this case, his conscience was wrong.
Yet, when our conscience alarm sounds, we should not arbitrarily dismiss it. It means that something appears to be wrong, even though we might not be able to immediately put our fingers on it. Thus, we should spend extra effort figuring out what is wrong. Paul talks about this at length in I Corinthians 10:25-33. Until we know, don't violate your conscience.
In the Bible, thoughts and emotions are ascribed to the organs of the body that respond to the thoughts and emotions. Thus the thoughts of the heart are those ideas that cause the heart to race. It often refers to ideas that a person strongly desires.
The kidneys ("reins" in the Kings James Version) is a vital organ. Taking an arrow in the kidneys meant dying a sure and painful death. Thus thoughts of the kidney referred to the deepest thoughts which were most vital in defining who a person is. Modern translations often switch the word from kidneys to mind. It is unfortunate because while it is easier to comprehend in our way of thinking, it loses some of the depth of expression.
"Thus my heart was grieved, And I was vexed in my mind" (Psalm 73:21). Emotionally he responded with grief, and inwardly he felt as if he was poked in the kidneys. That is, his innermost thoughts were twisting his gut, causing him pain.
It is not always bad feelings from deep within. "Yes, my inmost being will rejoice When your lips speak right things" (Proverbs 23:16). We would probably call this "butterflies in the stomach." It refers to deep excitement and happiness, the type where you can't eat because you're so happy.
"I will bless the LORD who has given me counsel; My heart also instructs me in the night seasons" (Psalm 16:7). Though it says "heart" in this translation, it is actually the kidney, the innermost thoughts that come to the surface during meditations in the night.
"Oh, let the wickedness of the wicked come to an end, But establish the just; For the righteous God tests the hearts and minds" (Psalms 7:9). That is, God tests men by their desires (the heart) and their innermost thoughts or motives (the kidney).