'Doubt' in the Bible

So your life shall hang in doubt before you; and you will be in dread night and day, and shall have no assurance of your life.

Immediately Jesus stretched out His hand and took hold of him, and *said to him, “You of little faith, why did you doubt?”

And Jesus answered and said to them, “Truly I say to you, if you have faith and do not doubt, you will not only do what was done to the fig tree, but even if you say to this mountain, ‘Be taken up and cast into the sea,’ it will happen.

Truly I say to you, whoever says to this mountain, ‘Be taken up and cast into the sea,’ and does not doubt in his heart, but believes that what he says is going to happen, it will be granted him.

And He said to them, “No doubt you will quote this proverb to Me, ‘Physician, heal yourself! Whatever we heard was done at Capernaum, do here in your hometown as well.’”