Excellent mantra - how throw those others thoughts away because they are totally false! I hope you don't mind if I interject a little of my personal thoughts regarding faith............. I believe that satan plants thoughts in our heads to deceive us and make us miserable - so when I have I thought that is destructive or damaging in any way I try to remember this simple little mantra -- "Those are not MY thoughts" and I push them aside.
Now for a bit of levity! I found this in an email and thought of you............ and all the other teachers in MDA-land.
I hope its not too small - If so I will edit............