I may have mentioned this already, but I'm reading through the Book of Joshua. Joshua is a very important figure in the Bible, but we don't hear much about the book's namesake. We hear a lot about Abraham, Moses, David, Solomon and others, but Joshua...not so much. But Joshua was used by God to fulfill the promises he gave to Abraham and Moses: he led God's people into the Promised Land! The trajectory of the first five books of the Bible is the establishment of the Promised Land and Joshua led the Israelites there. Quite an accomplishment! One could say that the book of Joshua could be accurately named "Eisago," the Greek word for "enter," just as Exodus is the Greek word for "exit."
Perhaps Joshua is not celebrated - at least in modern times - because of the violence and destruction that Joshua applied to the inhabitants of Canaan. It is well-documented that God required Joshua to completely conquer the territories and in the process kill many men, women, children and animals. What is less documented is the level of depravity that had overcome the Canaanites and the other inhabitants. These people were participating in idol worship, child and other human sacrifices, murder, and other deep offenses to God. They had become so depraved that their destruction was necessary.
Still...that was the Old Testament and not something that Jesus Christ would participate in or condone. After all, he came to bring peace to the world. Well, yes...and no. God the Father and God the Son are one God, with identical wills and purposes. God the Son does not argue or disagree with God the Father and vice versa; the same, of course, applies to God the Holy Spirit. The Second Person of the Trinity agreed with the destruction of Canaan. As a matter of fact, he led the charge:
When Joshua was by Jericho, he lifted up his eyes and looked, and behold, a man was standing before him with his drawn sword in his hand. And Joshua went to him and said to him, “Are you for us, or for our adversaries?” And he said, “No; but I am the commander of the army of the Lord. Now I have come.” And Joshua fell on his face to the earth and worshiped and said to him, “What does my lord say to his servant?”And the commander of the Lord's army said to Joshua, “Take off your sandals from your feet, for the place where you are standing is holy.” And Joshua did so.
According the Reformation Study Bible, "The commander is evidently an appearance of the pre-incarnate Son of God, The Divine Warrior and His army are prepared for war." In this passage, the commander of the Lord's army tells Joshua to remove his sandals, just as God told Moses to remove his because Moses - like Joshua - were in the presence of God. The same imagery is reflected in Revelation 19 when Christ returns as a warrior in the final acts of establishing his kingdom: "Then I saw heaven opened, and behold, a white horse! The one sitting on it is called Faithful and True, and in righteousness he judges and makes war."
The conquering of Canaan was a fulfillment of a promise made to Abraham and Moses, but it was also a judgment on the inhabitants of that land who had fallen into horrible sin and depravity. The final judgment of this world will be no different, led by the gentle Son of God filled with compassion and mercy for his people, and the fierce warrior filled with righteous judgment for those who refuse to bow the knee to Him.
The book of Joshua can be a hard read, but it - like the rest of the Bible - reflects the true, unchanging nature and character of God.