Michael Horton:

My conscience does not render a positive verdict in God’s courtroom when I look inside myself. The only reason I can sleep well at night is that even though my heart is filled with corruption and even though I am not doing my best to please him, I have in heaven at the Father’s right hand the beloved Son, who has not only done his best for himself but has fulfilled all righteousness for me in my place. [Christless Christianity: The Alternative Gospel of the American Church, 88]

HT: Of First Importance.