In the Old Testament, people would sacrifice animals to atone for sin. This was a way for us to tell God we realize that we screwed up and for us to follow specific guidelines He set up for us to show Him obedience.
Proverbs 21:3 tells us what is even better than atonement for our sins:
Doing what is righteous and just is more acceptable to the Lord than sacrifice.
Now, we will never be perfect. However, God finds favor with us when we make Godly decisions. Lets work more and more daily to be wise, not foolish.