Haggai 2:4
“Yet now be strong, O Zerubbabel, saith the Lord; and be strong, O Joshua, son of Josedech, the high priest; and be strong, all ye people of the land, saith the Lord, and work: for I am with you, saith the Lord of hosts:”
Speak now to Zerubbabel the son of Shealtiel, governor of Judah, and to Joshua the son of Josedech, the high priest, and to the residue of the people, saying,
Who is left among you that saw this house in her first glory? and how do ye see it now? is it not in your eyes in comparison of it as nothing?
Yet now be strong, O Zerubbabel, saith the Lord; and be strong, O Joshua, son of Josedech, the high priest; and be strong, all ye people of the land, saith the Lord, and work: for I am with you, saith the Lord of hosts:
According to the word that I covenanted with you when ye came out of Egypt, so my spirit remaineth among you: fear ye not.
For thus saith the Lord of hosts; Yet once, it is a little while, and I will shake the heavens, and the earth, and the sea, and the dry land;
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Cross-References
“Finally, my brethren, be strong in the Lord, and in the power of his might.”
“Watch ye, stand fast in the faith, quit you like men, be strong.”
“Be strong and of a good courage, fear not, nor be afraid of them: for the Lord thy God, he it is that doth go with thee; he will not fail thee, nor forsake thee.”
“Say to them that are of a fearful heart, Be strong, fear not: behold, your God will come with vengeance, even God with a recompence; he will come and save you.”
“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.”