Inner harmony is not a mystical esoteric concept not achievable for us mortals.
It is a simple and practical thing. Sounds simple, might be difficult to achieve, but the result is amazing.
If you want to see another guide to inner harmony, which explains everything better – it is here.
Positive thinking is not seeing a life through rose-coloured glasses.
It is a way to solve problems, to move forward, to achieve what you want. We understand that life is full of shit, but that does not stop us from enjoying it.
More about positivity you can find in a detailed article about this concept of thinking.