Jesus teaches in the gospels that sin comes from our hearts to our minds and to our senses and it becomes an act once is consented in the heart. But he condemns sin, before it becomes an act.
“27Ye have heard that it was said by them of old time, Thou shalt not commit adultery:
28But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.”
As you can see, the sin entered by the eyes, but it became sin by being consented in the heart.
The heart in the bible is often referred as the center of our desires and will power.
And he says the same about murder. To kill does not makes you a murder, the anger makes you a murder. But if you repent at the moment you are angry, and do not keep resentment in your hear by forgiving. Then, you are stopping the murder before if happened and you remain clean.
And the same cycle could go in reverse. Sins comes from the senses, to the mind to the heart. When we do bad things, starts a process of contamination. When we consent those things and start enjoying them, our hearts are already corrupted.
But when it comes to the heart, the transition is not that smooth. The Pharisees were doing good things by following the law, but their hearts were not pure. Therefore, they turned into bleached thumbs and blind teachers. They were hypocrites, because their hearts remained unclean. An evil heart produces bad thoughts and bad actions. A clean heart produces good thoughts and good actions.
But some manage to fake goodness and they even belief that they are good. This is the case of these religious leaders who did not cirncuncided their hearts.
16 So Jesus said, “Are you also still without understanding?
17 Do you not yet understand that whatever enters the mouth goes into the stomach and is eliminated?
18 But those things which proceed out of the mouth come from the heart, and they defile a man.
19 For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies.
20 These are the things which defile a man, but to eat with unwashed hands does not defile a man.”
Jesus gives us another example:
Two men went up into the temple to pray; the one a Pharisee, and the other a publican. The Pharisee stood and prayed thus with himself, God, I thank thee, that I am not as other men are, extortioners, unjust, adulterers, or even as this publican. I fast twice in the week, I give tithes of all that I possess. And the publican, standing afar off, would not lift up so much as his eyes unto heaven, but smote upon his breast, saying, God be merciful to me a sinner. I tell you, this man went down to his house justified rather than the other: for every one that exalteth himself shall be abased; and he that humbleth himself shall be exalted.
It seems the key for a good heart is humbleness and recognition of our sins. Because, God will forgive, but if we think that we have no sin, our sins are not forgiven. We need to ask.
When we spot sin before it actually happens as Jesus teaches, it’s easier to realize the condition of our hearts. Then we can see that we are not as good as we thought and that The Lord, really have to work on us.