I have this book, and I’m just not sure if it was written prior to reports of his conversion, of which I was not aware until seeing it just now in your post.
His writings center around a method of personal thought that reverses a difficult situation. Not so much a change in the outward circumstances, but by our inward application of Jesus’s “turning the other cheek” on the evil, which reduces its practical harm. I especially liked the chapter called “Resist not evil.”
Many christians are not aware of the harmful patterns of their thinking and how much they bind another person to us. Jesus warned us about holding another bound (Mt. 5:25), advising us to “Lose no time settling with our opponent - I warn you, you will not be released from prison until you have paid the last penny.” There are prisons beyond mere physical ones, and we have thought power to fasten chains to others spiritually.
When we release them from judgment in our thoughts and free them mentally, we also free them to embrace truth more readily. You may or may not believe this, but many of our thoughts do travel spiritually, and are not bound by the limited space of our brain. They are not so private as we think they are.
Some chapters of this book, I do not agree with, but there are occasional pieces of truth that might be helpful to you, as the Lord teaches you between the lines through the Holy Spirit enlightening your understanding…