This is the central portion of the charge given to the successor of Moses. Joshua was a very small man in comparison with his predecessor. He was no prophet nor constructive genius; he was not capable of the heights of communion and revelation which the lofty spirit of Moses was able to mount. He was only a plain, fiery soldier, with energy, swift decision, promptitude, self-command, and all the military virtues in the highest degree. The one thing that he needed was to be 'strong and courageous'; and over and over again in this chapter you will find that injunction pealed into his ears. He is the type of the militant servant of the Lord, and the charge to him embodies the duties of all such. I. We have here the duty of courageous strength. Christianity has altered the perspective of human virtues, has thrown the gentler ones into prominence altogether unknown before, and has dimmed the brilliancy of the old heroic type of character; but it has not struck those virtues out of its list. Whilst the perspective is altered, there is as much need in the lowliest Christian life for the loftiest heroism as ever there was. For in no mere metaphor, but in grim earnest, all Christian progress is conflict, and we have to fight, not only with the evils that are within, but, if we would be true to the obligations of our profession and loyal to the commands of our Master, we have to take our part in the great campaign which He has inaugurated and is ever carrying on against every abuse and oppression, iniquity and sin, that grinds down the world and makes our brethren miserable and servile. So, then, in these words we have directions in regard to a side of the Christian character, indispensable to-day as ever, and the lack of which cannot be made up for by any amount of sweet and contemplative graces.