2 Chronicles 20:6 (NKJV): And (Jehoshaphat) said, "O Lord God of our fathers, are You not God in heaven, and do You not rule over all the kingdoms of the nations, and in Your hand is there not power and might, so that no one is able to withstand You?"
Jehoshaphat and all of Judah were looking to God for help at a time when a great multitude was coming against them (see 2 Chronicles 20:1-2, 2 Chronicles 20:12). And the Lord gave them this assurance (through Jahaziel), "Listen, all you of Judah and you inhabitants of Jerusalem, and you, King Jehoshaphat! Thus says the Lord to you: Do not be afraid nor dismayed because of this great multitude, for the battle is not yours, but God's." (2 Chronicles 20:15) He (through Jahaziel) then continued, "You will not need to fight in this battle. Position yourselves, stand still and see the salvation ('yeshuwah') of the Lord, who is with you, O Judah and Jerusalem!" (2 Chronicles 20:17) The word 'salvation' ('yeshuwah') here can also mean 'victory, deliverance, aid, help, welfare, health (healing), prosperity'.
So (the next day), they rose early in the morning and went out into Tekoa; and as they went out, Jehoshaphat stood and said, "Hear me, O Judah and you inhabitants of Jerusalem: "Believe in the Lord your God, and you shall be established..." (2 Chronicles 20:20) The word 'Tekoa' here means 'the blast of the trumpet' (where victory is at hand), and 'be established' here means 'be strengthened, be strong, be assured, be firmed (or affirmed), be built up, be supported'. And what came after was an amazing victory for God's people (read 2 Chronicles 20:21-30). Praise God!
Let's go back now to the word 'stand' in 2 Chronicles 20:17. In cross reference, Ephesians 6:10-11 says, 'Finally, my brethren, be strong in the Lord and in the power of His might. Put on the whole armor of God, that you may be able to stand against the wiles (schemings) of the devil'. See the word 'stand' again? Here, it is 'histemi' in Greek, which, interestingly, means 'be established'! So, the apostle Paul was actually saying, "Put on the whole armor of God, that you may 'be established' against the wiles (schemings) of the devil."
Now, the big question many may ask: "How to be strong in the Lord?"
Not by your own self-effort (to fight the battle yourself) or by forcing yourself to be strong, but by 'putting on' the 'whole armor' of God! (see Ephesians 6:11-17) To 'put on' here is 'enduo' in Greek, which means 'endue with, clothe with, be filled with, fill your thoughts with, or be conscious of'. And who is this 'whole armor' of God? His name is Jesus! The 'whole armor' here also speaks of the 'wholeness, completeness, and fullness of God'! In other words, you become strong in the Lord by 'putting on' the 'whole armor' of God, i.e. by 'filling your thoughts with, or be conscious of' Jesus, who is your 'whole armor'!
Note: Of course, apart from 'putting on' the 'whole armor' of God, the apostle Paul also wrote, 'praying always with all prayer and supplication in the Spirit' (Ephesians 6:18).
The next question: "And you mean Jesus is my 'whole armor'?"
Exactly! Just an illustration here: Imagine yourself now in a bullet-proof armored car, or a military tank (armored vehicle carrying guns), knowing that nothing on earth can come against you (or hit you), and the feeling that you are safe in it! As a matter of fact, this whole armored car is stronger than you are (in the inside). So it is (the same) with you being 'clothed with' the 'whole armor' of God! To be in the 'whole armor' therefore means to be in Christ!
In Ephesians 6:14-17, the belt, the breastplate, the shoe, the shield, the helmet, and the sword are all 'pictures' representing the Person of Jesus Christ! So, it's not a question of what you do, or what is the 'whole armor' here, but knowing who you have, and who is your 'whole armor'! He is the Truth, He is your Righteousness, He is the Good News (Gospel) and the Prince of Peace, He is the Beginner (& Completor) of your faith, He is your Salvation (Yeshuwah), and of course, He is the Word of God! In short, He is your 'Whole Armor'!
People of God, the truth remains today that the 'enemy' can never withstand Him and His Word, whatsoever. Your God is stronger! In fact, He is stronger than any force of darkness on earth, or even all the forces of darkness in the spiritual realm put together! He is also stronger than any man's plan (or conspiracy) on earth, and infinitely stronger than all your challenges and problems (including health problems) on earth today. He is the same God yesterday, today, and forever (Hebrews 13:8) - in Jehoshaphat's time, in the apostle Paul's time when he wrote about the 'whole armor', now in your time, and even forever more. Know that victory is already yours. He has already won it for you at the cross. Believing, and you shall be established. Amen!