The sacrifices recorded in chapters five and six of Leviticus are meant to expiate offenses committed unwittingly or by inadvertence; they cannot substitute to the punishment due to premeditated crimes. But if not premeditated, why do we have to expiate them?
We look down on venial sins. We consider them of little significance, as a minor scratch on the surface of a shining car or a small abrasion in soft leather seats. We do not think twice about them and, as long as our sins are not mortal, we may not set foot in the confessional.
Why then does the Lord instruct Moses in the minutia of offering sacrifices for offenses committed out of ignorance or forgetfulness? Why is it necessary to make reparation for guilt we did not incur out of malice? Could it be that every act that violates the ten commandments or the commandments of the Church is offensive to God?
Picture a great artist who has just finished his masterpiece after toiling over it for ten years. Picture now a small child who walks by and playfully grabs a paint gun and fires at the painting. Will this act offend the artist? Will he be pained? Of course. Was the child guilty? No, because he did not know what he was doing. Still, his action, objectively, is an offense to the artist because it destroyed a beautiful painting.
Unwitting acts of malice are similar to the action of that child -- albeit not as innocent. They offend our Lord. This lecture will help you deepen your appreciation of God's holiness; the danger venial sins represent and the necessity of frequent confessions.