Deu 20:16-18 But in the cities of these peoples that the LORD your God is giving you for an inheritance, you shall save alive nothing that breathes, but you shall devote them to complete destruction, the Hittites and the Amorites, the Canaanites and the Perizzites, the Hivites and the Jebusites, as the LORD your God has commanded, that they may not teach you to do according to all their abominable practices that they have done for their gods, and so you sin against the LORD your God.
To them no offer of peaceful submission was to be made, and when the city was taken, all the inhabitants without reserve were to be destroyed. This was in accordance with God’s command to Israel and as a precaution against the risk of the people being seduced into idolatry by the heathen should they be allowed to remain in the land. (Unkown)
The horrors of war must fill the feeling heart with anguish upon every recollection; and are proofs of the wickedness of man, the power of Satan, and the just vengeance of God, who thus scourges a guilty world. But how dreadful their case who are engaged in unequal conflict with their Maker, who will not submit to render him the easy tribute of worship and praise! Certain ruin awaits them. (Henry)
But of the cities of those people, which the Lord thy God doth give thee for an inheritance,…. The cities of the seven nations, six of which are mentioned by name in the next verse: thou shalt save alive nothing that breatheth; the reason of this severity was because of their wickedness, the capital crimes and gross abominations they were guilty of, and for which they deserved to die; and on account whereof they were reserved to this destruction, when the measure of their iniquities was full. (Gill)
The previous commands regarding warfare did not apply to the upcoming conquest of Canaan. There, not only was Israel not to offer peace to the cities, but they were also to destroy everything, not only the adult males. This was a unique war of judgment, more than a war of conquest or defense. This explains why such a complete destruction was commanded. The culture of the Canaanites was so corrupt – socially, morally, and spiritually – that God considered it irredeemable, and ripe for judgment. In this unique war, the armies of Israel were to bring that judgment upon the Canaanites. (Guzik)
There were other times of God’s judgment upon mankind when God judged them irredeemable. In the time of Noah God judged all of mankind and destroyed every living thing but those on the Ark. Noah proclaimed God’s judgment for 120 years while he built the Ark. What did the people do? They mocked, ridiculed, and laughed at him and the thought of pending judgment coming.
Sodom and Gomorrah were judged and destroyed. The Assyrian army lost over 100,000 men in one evening. Jericho was judged and destroyed. There are other examples of God’s judgment and destruction that occurred on this side of eternity. The things that were an abomination to God for which these peoples were destroyed are not much different from what we see being declared. No reverence for God. Love of self. Self-reliance. Self-worthiness. Arrogance. Lusts of the flesh. Covetousness. Strife. Doing evil. Calling that which is good, bad. Calling that which is godly and holy, foolishness. Worshipping things other than God. Rejecting and denying God. Rejecting and denying Jesus Christ. Living in sin without a thought of God’s judgment. However, there is coming a time when everyone will stand before God and be judged.
Denying that judgment is coming allows a person to live according to whatever seems right in their own eyes. In this denial, everything seems permissible. No one ever born will be excluded from judgment. Everyone will stand before God to give account.
When people should be asking what can we do to be saved, they are proclaiming their sins, making excuses for their sinful ways, and encouraging others to do the same. Judgment is coming and those found in Jesus Christ will pass into eternal life, and those who chose to reject and deny Jesus Christ will be cast into the lake of fire and be tormented forever.