"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." (1 Chronicles 28:20)
This admonition--to be strong and of good courage--is found eleven times in the Bible--thrice on the lips of Moses, five times in Joshua, then twice from David, and once from Hezekiah. Although these all involved specific challenges confronting God's people at the time, the principles behind them indicate the need for courage of conviction for God's people at all times.
The first occurrence is in the command given by Moses to the Israelites just before his death as they were about to enter the Promised Land. "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" (Deuteronomy 31:6). In the next verse, Moses gave a similar exhortation to Joshua, their leader.
The next-to-last occurrence is in our text, containing almost the same words as in the first occurrence, with David this time exhorting Solomon to build the great temple in Jerusalem. Whether entering a new field of service for God or beginning a great work for God, the people of God will encounter opposition, and must be strong and courageous to carry it through.
The word "courage" occurs more in Joshua than in any other book of the Bible, and this specific exhortation is given five times: three by God, once by the people to Joshua, and once by Joshua to the people. In all these, the context stresses obedience to the Word of God, especially in resistance to sin and pagan belief systems. Especially significant is God's command: "Be thou strong and very courageous, that thou mayest observe to do according to all the law . . . that thou mayest prosper" (Joshua 1:7). HMM