“He who looks into the state of society around him, finds proof of man’s wickedness. Crimes abound everywhere; and the earth is filled violence, as it was of old. Laws restrain the crimes and violence of men; but the very necessity of laws demonstrates the wickedness of mankind. War and oppression make u, in great measure, the history of our race; and innumerable deeds of wickedness, which never find a place in the historic record, are written in God’s book of remembrance and will be brought to light in that day, when men shall be judged according to the deeds done in the body.
The actual transgressions of men consist in doing what God has forbidden, and in leaving undone what he has commanded. The latter are called sins of omission; the former, sins of commission. With both these kinds of transgression all men are more or less chargeable. They who abstain from grosser crimes have, nevertheless, committed many sins, and omitted many duties. But sin in the overt act, constitutes only a very small part of man’s sinfulness…
Moral depravity shows itself in outward acts of transgression; but, atrocious as these often are, it is chiefly in the heart that God beholds and hates it. “God saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually.” [Genesis 6:5] In the heart it was that God saw the great wickedness of the earth. The heart is a metaphorical term, denoting those mental affections which are the principles or beginnings of action. Here depravity exists at the very fountain from which all human action flow.”–from, The Fall and Present State of Man, Manual of Theology, J.L. Dagg
This is the kind of thing we’re talking about when we talk about sin. This is the kind of thing that needs forgiving. This is what Jesus is talking about in Mark 2:10. Thats the authority he’s talking about.