 If you give yourself over to the Course in Miracles workbook and you start on lesson one and you go through that, Jesus has designed the workbook to show you one thing that there is no inner and outer. That's what the whole point is. You're not going to ever have a question about if you change the inner then the outer will change because guess what? Ideas leave not their source. My thoughts are images I have made. My thoughts have not left the mind of the thinker. There is no outer. I'm simply looking on a motion picture in my mind of the thoughts that I still hold. And as soon as you get it back there from away from this inner outer thing, your problems are gone. Jesus says that there's no world apart from what you think. He says that in lesson 132. All the great non-dual teachings have taught the same thing throughout the centuries. There is no difference between the inner and the outer. So when you're at peace, guess what? You can't help but perceive a peaceful world because there is no world apart from what you think. If you're thinking the thoughts of God, thoughts of love, that heals the whole world because why? There is no external world outside of your mind.