Leviticus 5-6  Guilt offerings were required for a variety of reasons:

5:1 -When someone did not testify to something he had knowledge of.
5:2 - When someone touched something unclean, such as a dead animal.
5:3 When someone has touched someone unclean and doesn't know it, but then is made aware.
5:4 - When someone speaks thoughtlessly, swearing an oath to do evil or good.
5:15 -When someone unintentionally touches or uses something that is the "Lord's holy things"
5:17 - When someone sins by breaking a command, even if he isn't aware of it.
6:2 - When someone sins by deceiving another, robbing another,  or extorting another.
6:3 - When someone lies about finding what belongs to another

The guilt offering for the first four of these offenses are according to what the person can afford - a lamb or goat; 2 turtledoves or pigeons; or flour.   In any case, the sacrifice is offered for atonement and the person is forgiven.

When someone violates the holy things of God the sacrifice is to be a ram, which is evaluated according to the silver shekel plus a fifth part of it is added.
In the last 2 situations restitution must also be made.

In all these we learn that:
Whether sin is unintentional or we aren't even aware that we have sinned, we are still guilty. 
Guilt requires atonement.
Atonement requires a sacrifice.
When the sacrifice for atonement is made -sin is forgiven!

Oh Praise You Father for making a way for us to be forgiven!  We have all sinned and fallen short of Your glory.  We are all guilty.  Whether we are aware of what we have done or not... we are "certainly guilty before the Lord" ( 5:19).  Yet, the atonement offering has been made for us.  You have blessed us with every spiritual blessing - in Jesus Christ our Lord. "In Him, we have redemption through His blood, the forgiveness of our trespasses according to the riches of His grace, which He lavished upon us..."(Eph. 1:7) We bless Your Name. We praise You every day!  Thank You for Your grace and mercy upon us.  Thank You for having such a great love for us. Thank You for forgiving our sins and cleansing us from all unrighteousness.  Amen!