Use doubt to change.
The problem with doubt arises when we either don't transform it, or transform it into a negative emotion.
Feeling doubt from time to time is natural for all of us. It's a prerequisite for life, and there is nothing wrong with it.
On the contrary, doubt has a way of igniting transformation because it makes us reflect.
We get a more profound understanding of what's hiding underneath it, and can then transform it into clarity of mind and new actions.
The dark side
The problem with doubt arises when we either don't transform it, or transform it into a negative emotion, like guilt, for instance.
That's where it becomes dangerous because we are setting ourselves up for becoming a victim of our emotions.
It will lead us to frustration, which leads to anger, which leads to – well – the dark side.