The way I come to the knowledge of the immensity of sin is by contemplating the immensity of the grace that has met it.
"That in the ages to come He might show the exceeding riches of His grace in His kindness toward us, through Christ Jesus." This is the way the angels will learn, and the principalities and powers in the heavenly places, the meaning of "the exceeding riches of His grace." They will see the poor thief on the cross; the woman of the city that was a sinner; ourselves, too, seated in the heaven-lies in the same place and glory as God's dear Son!