!a lot about how we treat others.
You may have hidden sins in your heart, things you have said or done that you have not known them to be sinful. Anything that falls short of God's perfection is sin and we fall short of that all the time. Our concern should be that of the Psalmist and we should ask the Lord to cleanse us from those sins. We will never reach soul perfection this side of heaven so we must consistently seek the Lord's forgiveness for sin if we want to stay close to the heart of God.
Now, I know that the blood of Jesus cleanses us from all sin, that in Him we are made righteous and holy before God. I know that grace covers all of our sin and we don't have a need to spend every waking moment repenting of our sins. But, it is also true that we have a responsibility to want to live in purity of heart. We must want to make sure that there is no sin lurking in our hearts. And, the only way we can be sure that we are pure in heart is to confess our sins, both that which is known and that which is hidden, to Christ as the Spirit prompts us to pray for them.
It is good for the soul to regularly have a check-up, confess our sins, and keep our hearts pure before God.