The first key, put in a sentence, has been this: that our “evils” are never the happenings in themselves, but the effect we allow them to have on us. No matter whether objectively an experience is apparently good or evil, subjectively, to the one who fears and doubts, all is evil; to the one who trusts, all is good.
I started at the bottom and loved just one; and if you love one, you can love many; and if many, you can love all.