To ensure that His men would continue in the spiritual battle against evil to evangelize the world (Mt 28:16-20), Jesus establishes His Catholic Church on a “war footing” and His Kingdom on earth becomes known as the Catholic Church Militant.
God prepares and leads Israel in war
God leads the Jews out of Egypt and prepares them for the invasion war of Canaan through a grueling forty year march through the desert which is recorded in the Book of Numbers. Upon crossing the Jordan River, the men of Israel begin the violent conquest of Canaan and will fight dozens of wars over hundreds of years. Later, after being defeated and exiled, the Jews return to the Holy Lands and are violently subjugated under the Greeks and then the Romans. A fierce group of Jewish men lead the Maccabean revolt just prior to the Incarnation.
Consistent with the fighting history of the Jews and the very real threats which Jewish villages and travelers faced from robbers and thieves, Jewish fathers were required to teach their sons to fight and defend their villages. Swords were a common weapon which Jewish men carried (mentioned hundreds of times in the Bible), including Peter and other disciples at Jesus’ urging (Lk 22:36), and Jewish men also kept other weapons (bow/arrow, sling, staff) for both hunting and defense.
Jesus lays the foundation for His Catholic Church Militant
Building off of the militaristic foundations of His people Israel, God will now turn the fighting hearts of men from physical warfare to the spiritual warfare in the battle for the salvation of souls.
Because the Son of God always intended to return to His Father in Heaven after His Incarnation, He immediately begins to expand His army (“host”) to include mankind to carry on the spiritual battle to build His Kingdom after His Ascension. Immediately after His Baptism, Jesus announces His intention to build His Kingdom (Mk 1:14-15, CCC 541-542), recruits the Apostles (Mk 1:16-20, Mk 3:13-19) and soon renames Simon as Peter (meaning, “rock”), upon which He will build His earthly Kingdom (Mt 16:18-19, CCC 552); by all His actions, Jesus builds His Church for the salvation of mankind (CCC 763-766).
Jesus’ kingdom on earth is the Catholic Church Militant
Jesus’ Kingdom is called the Catholic Church (CCC 763-766). The Catholic Church derives its name from Catholic (meaning “universal”, CCC 830) and Church (meaning “convocation or assembly”; CCC 777) and exists in three states (CCC 954): the Church Militant (the pilgrims on earth), Church Penitent (the souls being purified in Purgatory), and the Church Triumphant (the Saints in Heaven).