In Joshua, chapter one, verse seven, for Joshua and the Israelites to possess the promised land, they had to commit to obey God’s written word. The Word of God was the central authority as opposed to all human ideas, traditions, or religions. This principle applies to believers under both the old and new covenants.
The central portion of the charge given to the successor of Moses is Joshua. Joshua was a small man in comparison with his predecessor. He was neither a prophet nor a constructive genius, not capable of the heights of communion and revelation that the lofty spirit of Moses was able to mount. Joshua was only a plain, fiery soldier with energy, swift decision, promptitude, self-command, and all the military virtues to the highest degree. The one thing that he needed was to be strong and courageous. Over and over again, Joshua lived up to his character of being such a person. The type of militant servant of the Lord and the charge to him embodies the duties of such.
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. Since the change of perspective, there is as much need in the lowliest Christian life for the loftiest heroism. For in no mere metaphor, but in grim earnest, all Christian progress is conflict. We have to fight the evils within, but we would be responsible for the obligations of our profession and loyal to the commands of our Master. We must take our part in the campaign He has inaugurated.
God is ever carrying on against every abuse, oppression, iniquity, and sin that grinds down the world and makes our brethren miserable and servile. So, in these words, we have directions regarding a side of the Christian character indispensable today as ever, and the lack of which cannot be made up for by any amount of sweet and contemplative graces.