'Good Courage' in the Bible

Be of good courage, and let us behave ourselves valiantly for our people, and for the cities of our God: and let the LORD do that which is good in his sight.

Then shalt thou prosper, if thou takest heed to fulfil the statutes and judgments which the LORD charged Moses with concerning Israel: be strong, and of good courage; dread not, nor be dismayed.

And David said to Solomon his son, Be strong and of good courage, and do it: fear not, nor be dismayed: for the LORD God, even my God, will be with thee; he will not fail thee, nor forsake thee, until thou hast finished all the work for the service of the house of the LORD.