11:5 If anyone tries to harm them, fire comes from their mouths and devours their enemies. This is how anyone who wants to harm them must die.

If anyone tries to harm them,

Apparently, the two witnesses' testimony angers the Jewish people first and the rest of the world second.

Why?

  1. If you believe in either a pretribulation or midtribulation 'rapture' , people who thought they were Christians and were left behind don't want to hear the Gospel/testimony (verse 7) again. They are guilty and too ashamed to admit it; their hearts are hardened.
  2. The AntiChrist as 'world leader' doesn't like what they say because they talk of the preeminence of Christ and not his.

There is an implication that these two witnesses can read thoughts by the use of the phrase "wants to harm them". They understand the intention of those around them. It is not clear that they also know of their death (verse 7) and restoration (verse 11).

fire comes from their mouths and devours their enemies.

This is a spoken judgment. Elijah was so anointed to 'speak fire' (2 Kings 1:9-10-12-16). Jeremiah 5:14 indicates Jeremiah was able to speak and the people were like wood.

Note the results of these spoken judgments:

This is how anyone who wants to harm them must die.

This is the second time the phrase "wants to harm" is used in this verse. This gives an emphatic clue to the way the world and AntiChrist will be "terminated". It is an 'eye for eye' principle.

Also, this is reactive witnessing (Matthew 12:9-15-16) as opposed to proactive witnessing, that is, attesting to signs, wonders, and miracles.