There is as much Scripture telling us that the 144,000 are going to sell hamburgers and fries as there is Scripture saying they are Jewish evangelists. There is not a single text which says that. It is just a made-up scenario to justify the otherwise bankrupt eschatological model of pretribulationism. Because pretribulationists assume the great tribulation to be the period of God's eschatological wrath, which it is not, they must remove the church first in the rapture. Then they need to explain the problem they created concerning the great multitude of all nations spoken of in Rev 7:9-17 who are standing before the throne having come out of the great tribulation. So, they take the 144,000 and call them evangelists, when no such thing is even hinted at in the scriptures.
Somehow, they have to go from the sudden absence of the Holy Spirit indwelt church, leaving the earth without a single believer and no witnesses preaching the Gospel to an innumerable multitude of believers coming out of the great tribulation. So, they make the 144,000 Israelite male virgins into the greatest evangelistic team the world has ever known, in the midst of a time of unparalleled persecution and supernatural deception. In fact, it is that time in which Jesus said many will be offended (depart from the faith) and betray one another and many will be deceived. We also read that following the various plagues of God’s wrath, “they repented not”. Yet pretribers are wanting to turn the darkest days (spiritually) in mankind’s history (future) into the greatest revival ever to take place.
The pretrib scenario is fantasy land. So many inventions are necessary to provide some continuity within the pretrib eschatological system. When thoughtfully considered it is incredulous.