Here are some more challenging quotes on sin:

Sin has cast this world into trouble.
You see the smoke and dirt of this trouble
spread throughout the pages of Scripture.
– Paul Tripp

Eve lays all the blame upon the serpent. 
Sin is a brat which nobody is willing to own,
a sign that it is a scandalous thing.
– Matthew Henry

It becomes us to speak of sin with the utmost dread and detestation
as an abominable thing; it certainly is so, for it is that which God hates,
and we are sure that his judgment is according to truth. 
Call it grievous, call it odious, that we may by all means possible
put ourselves and others out of love with it.
– Matthew Henry

We’ll never deal with temptation
unless we deal with it immediately,
unless we deal with it realistically,
unless we deal with it ruthlessly.
– Alistair Begg

Those that make light of sin, make light of Christ.
– Matthew Henry