Summary: Why praise can be a spiritual weapon.
How Praise can be a weapon in Spiritual Warfare
In the Old Testament
Israelites cross the Red Sea, the Pharoah and the Egyptians were destroyed. Moses and the Israelites began to praise the Lord.
The Lord is a man of war;
The Lord is His name.
Israelites saw how He defeated the Egyptians.
And it came to pass, when Joshua was by Jericho, that he lifted up his eyes and looked, and, behold, there stood a man over against him with his sword drawn in his hand: and Joshua went unto him, and said unto him, Art thou for us, or for our adversaries?
 And he said, Nay; but as captain of the host of the Lord am I now come. And Joshua fell on his face to the earth, and did worship, and said unto him, What saith my lord unto his servant?
The people was suppose to enter the land of Canaan. But the obstacles the wall of Jericho.
In this story we see God as the captain of the Lord
We seen Him as gentle father loving but there is another side to Jesus Christ, He is a mighty man of war.
PRAISE AS A SPIRITUAL WEAPON
2 Chron. 20:1
It happened after this that the people of Moab with the people of Ammon, and others with them besides the Ammonites, came to battle against Jehoshaphat.
2 Chron. 20:15 And he said, "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 Chron. 20:17 You will not need to fight in this battle. Position yourselves, stand still and see the salvation of the Lord, who is with you, O Judah and Jerusalem!’ Do not fear or be dismayed; tomorrow go out against them, for the Lord is with you."
2 Chron. 20:21-25 And when he had consulted with the people, he appointed those who should sing to the Lord, and who should praise the beauty of holiness, as they went out before the army and were saying:
“Praise the Lord, For His mercy endures forever."
 Now when they began to sing and to praise, the Lord set ambushes against the people of Ammon, Moab, and Mount Seir, who had come against Judah; and they were defeated.  For the people of Ammon and Moab stood up against the inhabitants of Mount Seir to utterly kill and destroy them. And when they had made an end of the inhabitants of Seir, they helped to destroy one another.  So when Judah came to a place overlooking the wilderness, they looked toward the multitude; and there were their dead bodies, fallen on the earth. No one had escaped.  When Jehoshaphat and his people came to take away their spoil, they found among them an abundance of valuables on the dead bodies, and precious jewelry, which they stripped off for themselves, more than they could carry away; and they were three days gathering the spoil because there was so much.
Praise lifts your eyes from the battle to the victory, for Christ is already Victor, and you have the Victor in your heart that you might have His victory in your life. It is interesting to see that the opposite of praise to blame. Could it be when we don’t praise Him we are angry with God and blaming Him for a situation in our life