Just read the famous quote from Rabbi Schnuer Zalman of Liadi which sums up Jewish mysticism’s practical approach to self-help, growth, happiness and world peace.
A little bit of light banishes a lot of darkness
Now the explanation is far deeper than light and darkness
Rabbi Schnuer Zalman teaches us that within us there is a little devil – Yetzer Hara – a demon who constantly constantly constantly lies to us.
The fundamental lie is that G-d does not run the world and hence things are dark
Just shout at your Yetzer Hara “You are a repulsive barbaric liar, even your existence is only possible, how much more so mine, if G-d controls, creates, animates and loves us.”