When the servant of the man of God got up early and went out, he discovered an army with horses and chariots surrounding the city. So he asked Elisha, “Oh, my master, what are we to do?”
Elisha said, “Don’t be afraid, for those who are with us outnumber those who are with them.”
Then Elisha prayed, “LORD, please open his eyes and let him see.” So the LORD opened the servant’s eyes. He looked and saw that the mountain was covered with horses and chariots of fire all around Elisha.
2 Kings 6:15-17 HCSB

2 Kings 6:15-17
Since Gehazi had been dismissed as a disobedient servant and “leper” (2Ki_5:27), the Naaman story must follow this one if Elisha’s servant here is Gehazi. Or this servant may be someone who replaced Gehazi. Early the next morning the servant was terrified to see that the whole city was under the Arameans’ control, or so he thought. He returned in a frenzy to Elisha and nervously asked, What shall we do? The servant’s anxiety reflected his lack of understanding and trust in the Lord which, one would think, Elisha’s previous revelations would have changed.
Elisha was not at all disturbed by the present situation. He encouraged his aide to stop fearing, and assured him that they had behind them a force superior to that of the enemy. Elisha then asked the Lord to enable his servant to see this host and the Lord did so. He gave the servant the ability to see the normally unseen world of invisible spirits (angels) that are constantly ready to do God’s bidding (cf. Gen_28:12). The hills around Dothan were filled with superior horses and chariots. These appeared as fiery agents of God suggesting to the servant their superterrestrial origin (cf. 2Ki_2:11). The Lord had surrounded the armies of Aram and was in control.
Bible Knowledge Commentary

Angels are the servants of God, they are also the warriors of God.

May the lord open your eyes to his work.