Here is a record of a powerful prayer case: Why were the simple and short prayers effective in all cases?
Because Elisha could see the spiritual realm. He had faith as he was not looking at the seen, but at the unseen. He saw in his spirit. He knew His God. He trusted God would send him more horses and chariots than the enemy had. He knew what he had in the spiritual realm was real and he had already won the battle. David heard the marching of God's army in the spiritual realm and then sent out his own physical army, just as the Lord had told him, and he won the battle. The heavenly forces made sure of David's and Elisha's respective victory.
How did Elisha make sure what he had in the spiritual manifest in the physical? He prayed effectual prayers by faith. Effectual prayers produced results we need for victory in life.
Jesus said, in HIs name, what we bind on earth will be bound in the spiritual realm. Do we march with the heavenly army?
2 kings 6:15-20 (Boldness of letters added)
When the servant of the man of God got up early the next morning and went outside, there were troops, horses, and chariots everywhere. “Oh, sir, what will we do now?” the young man cried to Elisha.
16 “Don’t be afraid!” Elisha told him. “For there are more on our side than on theirs!” 17 Then Elisha prayed, “O Lord, open his eyes and let him see!” The Lord opened the young man’s eyes, and when he looked up, he saw that the hillside around Elisha was filled with horses and chariots of fire.
18 As the Aramean army advanced toward him, Elisha prayed, “O Lord, please make them blind.” So the Lord struck them with blindness as Elisha had asked.
19 Then Elisha went out and told them, “You have come the wrong way! This isn’t the right city! Follow me, and I will take you to the man you are looking for.” And he led them to the city of Samaria.
20 As soon as they had entered Samaria, Elisha prayed, “O Lord, now open their eyes and let them see.” So the Lord opened their eyes, and they discovered that they were in the middle of Samaria.