Thought and character are one, and as character can only manifest and discover itself through environment and circumstance, the outer conditions of a person's life will always be found to be harmoniously related to inner state.
There's not much to say about this book, which is all about our thoughts and how they shape reality, other than to say it was excellent. I did find there was quite a bit of repetition, but this may have been intended. As it was written so long ago the language used was a bit hard to get used to, but the message was powerful. It's very short, at around 50 pages, so it definitely deserves a read.
Train your mind in strong, impartial, and gentle thought; train your heart in purity and compassion; train your tongue to silence, and to true and stainless speech; so shall you enter the way of holiness and peace, and shall ultimately realise the immortal love.