From A. W. Tozer - The Danger of a Shallow Faith
 
"Backsliding always  begins with the heart.  People blame other circumstances and say, 'It's my home life,  It's the place where I work.  It's the school.  It's because I was ill, or it was because I had to work too much.  It's because I didn't have time.'  Those are external things; backsliding begins in the heart."