How can one tell the difference between a genuine "Elijah" message that God sends, and a clever counterfeit?

How can one tell the difference between a genuine "Elijah" message that God sends, and a clever counterfeit? When God fulfills His promise to send "Elijah the prophet before the coming of the great and dreadful day of the Lord" (Mal. 4:5), there will be very certain evidences:

(1) The message will be as unpopular as Elijah's was in his day. The news of what Elijah said to King Ahab about "no rain" flew throughout the kingdom like word goes on the Web today. Many far and near will condemn it while at the same time the message will "go" far and near.

(2) The message will be uncomfortable to those who love sin and worldliness, because it will be inspired by a Visitor, the Holy Spirit, whose first work is to "convict ... of sin" (John 16:8).

(3) Elijah's message will proclaim full religious freedom. To those in Israel who wanted to worship Baal, Elijah gave the ultimate in opportunity. Risking his life on Mt. Carmel, he invited the 450 prophets of Baal to do their thing before everybody. Gave them full access to the media of the day. It was a full, unhindered demonstration of Baal worship. It follows that in these last days, the true Christ will give full liberty to "Baal" to do his thing--publicity, swollen budgets. Let the people have a big dose, so they can get sick of it on their own. There might even be something to that proportion of 450 to 1. When the final showdown comes, as it was on Mt. Carmel, we read that when the storm at last begins to blow, multitudes of what we have thought were true disciples will be like "dry leaves," like in Jesus' day when "many of His disciples went back, and walked with Him no more" (John 6:66).

(4) "Elijah" will have a positive message, as he had on Mt. Carmel. He didn't spend his precious time railing against Baal worship, but re-built the broken down altar of the true God, and called on the people to see what happens when His worship is restored.

(5) The fruit of Elijah's message? A national repentance: "When all the people saw it, they fell on their faces: and they said, 'The Lord, He is God!'" (1 Kings 18:39). As in John the Baptist's fulfillment of the Elijah message, so the message that comes "before the coming of the great and dreadful day of the Lord" will "make ready a people prepared for the Lord" (Luke 1:17).

It appears that "the third angel's message in verity" (Rev. 14:1-12) and the "Elijah message" are the same: repentance permeating the "body of Christ."