The doubt means –

Lack of trust, to loose confidence, to be in a state where one doesn’t believe, to disagree, to loose faith.

Having negative thoughts which stops a person from believing, or acting towards what he or she has heard.

In Hebrew the state of doubting derives from the word called Amalek – and the word Amalek comes from the Hebrew root word called Shafek.

Shafek meaning to doubt, to loose faith, to enter into a mode of fear, to be attacked by the negative thoughts of terror, to feel insecure..

1 John 4:18:

There is no fear in love; but perfect love casts out fear, because fear involves torment.

But he who fears has not been made perfect in love.

Self-doubt occurs when we are lack of confidence or feeling incapable of doing things we need to do.

People who have doubts about themselves panic about things, being in an emotional state where one thinks that things would go out of control or not going the way as expected. …

The negative energy of fear is one of the root cause of what can become thoughts of doubt or doubting, which occurs in one’s mindset or pattern of thoughts.

However, persistent fear and self-doubt can hugely affect your life, in a bad way.