Then she bore again, this time his brother Abel. Now Abel was a keeper of sheep, but Cain was a tiller of the ground. And in the process of time it came to pass that Cain brought an offering of the fruit of the ground to the Lord. Abel also brought of the firstborn of his flock and of their fat. And the Lord respected Abel and his offering, but He did not respect Cain and his offering. And Cain was very angry, and his countenance fell.
So the Lord said to Cain, "Why are you angry? And why has your countenance fallen? If you do well, will you not be accepted? And if you do not do well, sin lies at the door. And its desire is for you, but you should rule over it."Now Cain talked with Abel his brother; and it came to pass, when they were in the field, that Cain rose up against Abel his brother and killed him.
Then the Lord said to Cain, "Where is Abel your brother?" He said, 'I do not know. Am I my brother's keeper?' And He said, 'What have you done? The voice of your brother's blood cries out to Me from the ground. So now you are cursed from the earth, which has opened its mouth to receive your brother's blood from your hand. When you till the ground, it shall no longer yield its strength to you. A fugitive and a vagabond you shall be on the earth.'
And Cain said to the Lord, 'My punishment is greater than I can bear! Surely You have driven me out this day from the face of the ground; I shall be hidden from Your face; I shall be a fugitive and a vagabond on the earth, and it will happen that anyone who finds me will kill me.'" Genesis 4:2-13
God means what He says and God required a lamb. When Abel's offering was accepted and Cain's was rejected, rather than amending his ways by turning to God with repentance he silenced Abel by killing him since his life was a rebuke to his own sins. Many professed believers are in no better a position than was Cain. While they claim to worship God they expect to be accepted while substituting their own standard of righteousness for God's requirements and blame God and others rather than face their own sins.
Also, isn't it interesting how some people will be just fine with harming others yet when their experience is much less than what they put others through claim is too much for them to bear? Self-righteousness is always caused by a warped view of reality and leads to devaluing others due to the root problem of inflated self importance. Cain considered his punishment to be greater than he could bear because he didn't have a clear view of the greatness of his crime. In reality it wasn't a very harsh sentence at all in light of murder. God could have blotted Cain out of existence instantly. If he had a clear understanding of his own sin, he would have seen how undeserving his was to even be allowed to live another day to work the ground and would have been grateful rather than complain about it.
Yet while Cain thought it was too terrible to have to work harder, he didn't seem to think the crime of killing his brother was too much to bear or his own actions were too harsh. This clearly is not true repentance for sin. He was sorrowful for the results but he didn't show sorrow for his sin or acknowledge it. He even blamed the natural results of his sin on God by claiming God was the one who hid His face from him and caused him to be a fugitive and a target for revenge rather than acknowledging his own faults. And many people do that today, yet God lets us know it is wrong.
"Behold, the Lord's hand is not shortened, that it cannot save; nor His ear heavy, that it cannot hear. But your iniquities have separated you from your God; and your sins have hidden His face from you, so that He will not hear. For your hands are defiled with blood, and your fingers with iniquity; your lips have spoken lies, your tongue has muttered perversity. No one calls for justice, nor does any plead for truth. They trust in empty words and speak lies; they conceive evil and bring forth iniquity." Isaiah 59:1-4
It is very important to be honest with ourselves and truly repent instead of making excuses for sin. Overtime we can become so self deluded and we can lie in the face of God Himself and not acknowledge our sins. Keep in mind whenever we sin we do so in the full view of God. You cannot hide it, so there is no point in denying it. And remember obedience to God isn't about doing what you deem best, it is about God's best for you-no substitutes. "The sacrifice you desire is a broken spirit. You will not reject a broken and repentant heart, O God." Psalm 51:17
Picture originally found here