And he performs GREAT SIGNS, so that
These are no mere tricks; these are supernatural such that humans, individually or collectively, would have a difficult time devising them. Their purpose is the LEAD ASTRAY even the elect (next verse, Matthew 24:24).
Interestingly, when it was demanded of Jesus to show a SIGN (Matthew 12:38-45), he didn't do it but rather pointed the requester to Jonah and the Old Testament prophets. When a person is living an "unbelieving" life, they will constantly ask for SIGNS. That is what keeps fortunetellers and the like busy. The true believer, on the other hand, is trying to please God through FAITH (Hebrews 11:6).
he even makes FIRE come down out of HEAVEN to the EARTH in the presence of men.
Now this FIRE must be permitted by God. It is not unlike that described in Job 1:16 at least as it was perceived to be. That the earth beast can do this shows the kind of AUTHORITY he has received (previous verse).
This kind of FIRE is well understood by Jewish people. They have heard how Elijah called it down (1 Kings 18:30-40, 2 Kings 1:9-16). They have had, most recently, two witnesses who breathed fire out of their mouths in self defense (Revelation 11:5). So fire has been used as a SIGN and defense before.
But the ultimate use of FIRE is in judgment, and, in particular, judgment associated with authority. The disciples, James and John, after receiving their "authority", wanted to call down fire on a Samaritan village (Luke 9:51-56). Incidentally, the village didn't get burned.
The final judgment for the sea beast and the earth beast (false prophet), as you recall, will be FIRE, Revelation 20:9-10.