GOD is our only STRONG DEFENSE against the ENEMY ATTACKS: "Now it came to pass in the ninth year of his reign, in the tenth month, on the tenth day of the month, that Nebuchadnezzar king of Babylon and all his army came against Jerusalem and encamped against it; and they built a siege wall against it all around. So the city was besieged until the eleventh year of King Zedekiah. By the ninth day of the fourth month the famine had become so severe in the city that there was no food for the people of the land. Then the city wall was broken through..." (2 Kings 25:1-4)
The southern kingdom of Judah had a total of twenty kings in the line of King David, but only eight kings did well in God’s sight. After three years of submission to the Babylonians, King Zedekiah, the last of David’s descendants, foolishly rebelled against the Babylonian occupation (24:18-20) that resulted in Nebuchadnezzar’s final siege of Jerusalem for over eighteen months. In 586 B.C. Jerusalem fell to the Babylonians when the walls were breached (25:4), and the southern kingdom of Judah was taken captive. Zedekiah tried to escape but was captured, blinded, and deported to Babylon (25:4–7) where he died eventually, and his sons were killed before his very eyes. What a tragic end to this seemingly impregnable walled city of Jerusalem!
The primary means of defense for a city in the ancient world was its wall. The stronger the wall was the greater was the security of the city. Also, other factors that helped in protecting the city included the geographical terrain where the city was built and the source of water to the city. However, the greatest protection for any city was its wall (e.g. Jericho, see Josh. 6:1; Nineveh, see Nah. 2:6–8; Babylon, see Dan. 5:30–31). The Word in Life Study Bible lists five ways to capture a walled city including scaling the walls, breaking through the walls (with battering rams), tunneling under the walls, through a siege (by cutting off outside resources), and through deception or negotiations. However, once the enemy breached the wall, the city was almost certain to fall – like it did for Jerusalem as well (v. 4).
Even though Jerusalem had all the defense mechanisms to withstand the Babylonian army, their defense failed miserably. The main reason for the failure of the city of Jerusalem can be attributed to the fact that Jehovah God had withdrawn His Hand of protection from Jerusalem earlier due to the fact that both the king and the people of Jerusalem had committing evil before God and had disobeyed His commandments. This is how the scriptures give the reason: "Surely at the commandment of the Lord this came upon Judah, to remove them from His sight because of the sins of Manasseh, according to all that he had done, and also because of the innocent blood that he had shed; for he had filled Jerusalem with innocent blood, which the Lord would not pardon" (2 Kings 24:3-4).
Let us never forget that God is our only strong defense against the attacks of the enemy. Today, we have only one enemy: Satan and his demons "for we do not wrestle against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this age, against spiritual hosts of wickedness in the heavenly places" (Eph. 6:12). Our enemy Satan is like a roaring lion seeking whom he may devour, so we must be sober and vigilant always (1 Peter 5:8). We should put on the whole armor of God in order to stand against the wiles of the devil (Eph. 6:11, 13-17). Even with the whole armor of God, we should pray fervently and watch out with perseverance (Eph. 6:18) so that Satan will not catch us off-guard. This may be the reason why Jesus taught us to pray this sentence as well: "but deliver us from the evil one" (Matt. 6:13).