While we all at times reason with others, and may even reason with God, our primary mode of reasoning is in our hearts. Some have relegated the realm of the mind, intellect, and reason to the soul, but Jesus makes it abundantly clear that when we reason, we reason in our hearts. Consider the following scriptures.
"But some of the scribes were sitting there and reasoning in their hearts, 'Why does this man speak that way? He is blaspheming; who can forgive sins but God alone?' Immediately Jesus, aware in His spirit that they were reasoning that way within themselves, said to them, 'Why are you reasoning about these things in your hearts?'" (Mark 2:6-8)Reasoning is not a soulish activity but rather a process that takes place within our hearts.
"But Jesus, knowing what they were thinking in their heart, took a child and stood him by His side..." (Luke 9:47)
The problem with our reasoning is not the process itself, but rather that it is limited and affected by the condition of our heart. If our heart is clean and pure, then so will be our reasoning, but if our heart is polluted by sin, then too will be our reasoning. "To the pure , all things are pure; but to those who are defiled and unbelieving, nothing is pure, but both their mind and their conscience are defiled." (Titus 1:15) Here are some examples from the scriptures of how the condition of our heart can affect the quality of our reasoning.
"Their inner thought is that their houses are forever and their dwelling places to all generations; they have called their lands after their own names." (Psalms 49:11) When our hearts are full of pride we loose sight of the brevity of life. We will not live forever nor will our works. Pride causes us to misjudge the things that are of first value and can lead us to pursue things that temporal and passing away.
"Abraham said, 'Because I thought, surely there is no fear of God in this place, and they will kill me because of my wife.'" (Genesis 20:11) Abraham judged king Abimelech and the people of Gerar, not based upon facts or observations, but rather based on presumption and prejudices. Presumption blinds us to the truth and distorts our vision of reality.
"These things you have done and I kept silence; you thought that I was just like you; I will reprove you and state the case in order before your eyes." (Psalms 50:21) Just because we believe something does not make it true. Believing as true that which is really a lie is called deception. Regardless of the source of the deception, it will keep us from obtaining the truth as long as we insist in holding on to it.
"Then Hezekiah said to Isaiah, 'The word of the Lord which you have spoken is good.' For he thought, 'For there will be peace and truth in my days.'" (Isaiah 39:8) God had just declared judgment against Israel, ye Hezekiah received it as a "good" word. He failed to grasp the gravity of the word of God because his heart was selfish and he thought only of himself.
"And Jesus knowing their thoughts said, 'Why are you thinking evil in your hearts?'" (Matt hew9:4) When we harbor evil motives in our heart we are no longer able to judge between good and evil; evil becomes good and good becomes evil. When we reason with evil motives, we always arrive at the wrong conclusions.
"The Lord knows the reasonings of the wise, that they are useless." (1 Corinthians 3:20) When, in our hearts we reject the knowledge of God, then our reasoning becomes futile. It is only when we open ourselves up to, and submit to, the wisdom of God can we reason effectively and grow in our knowledge, understanding, and insight.
"When I was a child, I used to speak like a child, think like a child, reason like a child; when I became a man, I did away with childish things." (1 Corinthians 13:11) It is the Father's will that we would grow in our knowledge and understanding and in our ability to reason well. While we are born again as a babe in Christ, we are not to stay a babe, but we are to grow up in the knowledge and love of God. At times this will mean putting away some of our childish reasonings that we might learn to reason as an adult.
"For she thought, 'If I just touch His garments, I will get well." (Mark 5:28) While the scriptures are replete with examples of how the condition of our heart can negatively impact our ability to reason well, here is an example of how a heart of faith can lead us to healing and freedom. When faced with the hopelessness of her situation, this lady reasoned with faith and, in reasoning with faith, she was not disappointed.