Thomas Boston, Works, 6:448:
Labour to see sin in its own colours, what an evil thing it is, Jer. 2:19. What makes us to cleave to sin, is false apprehensions we have about it. To see it in itself would be a means to make us fly from it.
Source: http://www.puritanboard.com/f25/see-sin-its-own-colours-85368/, Comment #1