Method of War
Wars in the Old Testament were all fought with swords, bows and arrows, weapons and chariots. However, in the New Testament era, the rules of warfare have already changed, and the most powerful weapon is no longer any military equipment, but the "Word of God"!
Let us first take a look at the military equipment in the New Testament:
Ephesians 6:13-19. Therefore take up the full armor of God, so that in the day of tribulation you may resist the enemy, and when you have done it all, you will be able to stand. Therefore stand firm, gird your loins with truth, and cover your breasts with righteousness as a breastplate. And put on your feet with the gospel of peace, as shoes for preparation. In addition to taking faith as a shield, the rockets that will quench all the wicked ones. And put on the helmet of salvation, and take the sword of the Holy Spirit, the word of God. By the Holy Spirit, always with all prayers and supplications, and watch here with perseverance, praying for all the saints, and for me, that I may gain eloquence, that I may speak with boldness the mysteries of the gospel.
Almost all gear, including girdle belts, breastplates, shields, helmets, shoes, etc. are for protective purposes. There are only two weapons to attack the enemy. One is to use the Word of God as a sword; and the other is Prayer. Yes, both weapons are WORDS!
It can be clearly seen that the method of war has changed from using swords to using words! That is why Paul did not ask God to give him helpers or any physical weapons, but to grant him eloquence so that he could preach boldly the Word of God!
Object of War
In addition, the object of warfare is also different from the Old Testament. The enemy in the Old Testament were often armies and citizens of foreign nations, but in the New Testament, the enemy was the Devil and evil spirits which control mankind in the spiritual realm.
Ephesians 6:12. For we are not at war with flesh and blood, but against those who rule, and those who are in power, and those who rule over this dark world, and the spiritual demons of the heavens.
Why is there such a change? It is because in the Old Testament, all people sinned and fell under the control of the Devil which made them fight against one another. However, when Lord Jesus came In the New Testament, He set His believers free by atoning for the sins of the world. These people become a peaceful community under God, but the devil is unwilling to let them go. We must therefore fight against the Devil and demonic spirits, resist their attacks, and take back the souls and God's gifts that the Devil has robbed from us.
Demonstration of War
In the New Testament, there are many demonstrations of wars with the Devil:
When Lord Jesus was fasting in the wilderness, he used God's Words to fight off the Devil three times.
Lord Jesus used His Word many times to cast out demons.
Lord Jesus rebuked the storm and ordered it to stop.
The disciples who were empowered by Lord Jesus also cast out demons with their words.
After the ascension of Lord Jesus, many believers have received the Holy Spirit. Likewise, Peter, Paul, and other disciples also cast out demons with their words, and gave testimonies everywhere.
Ending of the Wicked
Ignorant monarchs in the modern times, being unaware that the rules of war have already changed, keep investing in military structures and armaments. However, with one word from God, they will perish!
In the book of Revelation, we can see the laughable ending of the wicked. When Satan was released after being bound for a thousand years, he gathered a big crowd to fight against God, and the number was "as many as the sand of the sea". However, without using a single man, God destroyed them all by simply calling down a fire!
Permanent Peace
In God's New World, there will be no more bloody wars, and no more military weapons. Let us take a look at the prophecy in Isaiah:
Isaiah 2:4. ...they will beat their knives into plowshares and their guns into scythes. One nation does not raise its sword against another nation, nor do they learn war any more.
Weapons have been turned into farming equipment! There will be no more wars, and the world finally attains permanent peace!