Grateful not grumbling...
Could purity of thought include positive thinking? If we box in the concept of purity with the rigid confines of sex and intimacy, we're missing all the areas of our lives that can so easily be targets of impure thoughts and feelings.
(NIV) Proverbs 15:26 says, "The LORD detests the thoughts of the wicked, but those of the pure are pleasing to him."
When I am moaning and groaning and whining about what I don't have and how unfair my circumstances are, I can sound as wicked as any witch in the East or the West. I can whine about having nothing to wear, but when I move from grumbling to grateful the tables are turned.
My thoughts determine my attitude and by walking in the PURE light of His blessings, I am not a puppet who is responding to life based on the fleeting material inadequacy I may be saddled with in the moment.
So often I battle my 'flesh woman'....the part of me that judges others quickly and makes snap decisions based on external appearances. I fail to see things through the shadow of the cross. I want to jump to conclusions and analyze others actions through my skewed lens of personal perspective rather than stepping back and seeing a new viewpoint.
God's reflection is so much larger, it covers more ground than I can even recognize when I'm grumbling and passing judgement about what I think I see at the moment. He covers every situation with His PURE grace and until I begin to frame my encounters with the shadow of the cross, my potentially gratefully heart will stay hidden.