Susannah Wesley

Whatever weakens your reason, impairs the tenderness of your conscience, obscures your sense of God, or takes off the relish for spiritual things then it is sin for you, however innocent it may be in itself.

Tracy Chapman

Here I am waiting for a better day
A second chance
A little luck to come my way
A hope to dream a hope that I can sleep again
And wake in the world with a clear conscience and clean hands
'Cause all that you have is your soul

William Jay

I only add that I love a laugh when it leaves no sting in the conscience, or stain upon the mind; and that such a laugh cannot be disagreeable to your uncle in his long solitudes and (I love to hear him laugh, he does it so heartily) ....

(In a letter of 1838 found in his writings)