Satan was able to appear to Jesus in the flesh.

Compare the story in Matthew chapter four. Both knew who the other was. Satan has been granted considerable latitude in testing and trying to seduce men. He tries to get Jesus to worship him, and fails. He is “the ruler of this world” Jn 12:31. He is allowed to make great offers to Jesus.

“8 Again, the devil took him to an exceedingly high mountain, and showed him all the kingdoms of the world, and their glory. 9 He said to him, “I will give you all of these things, if you will fall down and worship me.””
Mtt 4:8-9 WEB

Yes, though constrained to this creation in our day, Satan has much power, but that is not all of the story.

Elisha was in a terrible bind in 2 Kings chapter 6.

The King of Aram has Elijah surrounded in the small town of Dothan. What the Hebrew text calls “Aram,” the KJV calls Syria (which it is today.) When Elisha’s servant arose the next day, look! The whole city was surrounded by horses and chariots. He asked Elisha, What shall we do?

Greater are those who are with us

“16 He answered, Don’t be afraid; for those who are with us are more than those who are with them. 17 Elisha prayed, and said, Yahweh, Please open his eyes, that he may see. Yahweh opened the eyes of the young man; and he saw: and, behold, the mountain was full of horses and chariots of fire round about Elisha.”
2Kfs 6:16 WEB

But it not just the number of men versus the number of angels, or even of good angels versus bad angels.

“What then shall we say about these things? If God is for us, who can be against us?”
Rom 8:31 WEB

We as Christians have the living God Himself living in us, if we stay with Him.

“Don’t you know that you are a temple of God, and that God’s Spirit lives in you?”
1Cor 3:16 WEB

What good news it is to have Yahweh God Himself as our deliverer. Or as the apostle John put it,

“You are of God, little children, and have overcome them; because greater is he who is in you than he who is in the world.”
1Jn 4:4 WEB

Or as the psalmist put it,

“Though he stumble, he shall not fall,
For Yahweh holds him up with his hand.”
Psa 37:24

What is it then that can overcome us?

“38 For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers, 39 nor height, nor depth, nor any other created thing, will be able to separate us from the love of God, which is in Christ Jesus our Lord. ”
Rom 8:38-39 WEB

Powerful enemies for us? Yes! But powerful supporters also.

and book of Revelation?

It is a series of parallel overlapping visions which show … many trials? Yes. And ultimate victory! Also yes!

WEB is the World English Bible, a copyright free revision
of the original ASV American Standard Version 1901