7 is a Psalm about God's judgment based on what you do. If this strikes you as a bit scary, it should. If this strikes you as over-simple, congratulations you posses higher level moral thinking. There are people, children and adults who decide questions of right and wrong based on what causes them harm or causes them pleasure. Since the Lord is the God of all people, he speaks in his Word to those who think about right and wrong in this simple way because God wants us to follow him and love justice, and it is good for us to do so.
Ask God to increase your love of what is right, and to forgive your shortcomings.