Genesis 4:5-7 (The Message)
3-5 Time passed. Cain brought an offering to God from the produce of his farm. Abel also brought an offering, but from the firstborn animals of his herd, choice cuts of meat. God liked Abel and his offering, but Cain and his offering didn't get his approval. Cain lost his temper and went into a sulk.
6-7 God spoke to Cain: "Why this tantrum? Why the sulking? If you do well, won't you be accepted? And if you don't do well, sin is lying in wait for you, ready to pounce; it's out to get you, you've got to master it."
It is normal for we humans to make mistakes. As we see from this passage of scripture, Cain messed up with his sacrifice. The problem here is that Cain couldn't admit his error and learn from his mistake. He instead became jealous and resentful of his brother. If you remember the story, Cain's anger led him to murder Abel.
It is critically important that we don't allow our mistakes to fester and lead us into more harmful thoughts and behaviors. God warned Cain that sin was just waiting to trip him up, and that goes for us as well. We need to admit when we are wrong, so that we can be forgiven and be given the opportunity to get it right.
We need to get it right not just with God, but with each other. Our relationships with one another depend on us owning up to our faults. Don't pretend to be perfect; learn from the mistakes and grow as an individual. When you can admit that you are wrong, then you are right!