Who are the Two Witnesses
Behold, I will send you Elijah the prophet before the great and terrible day of the Lord comes. (Malachi 4:5)
Before Jesus made His official debut, God sent a “witness” to prepare the world. The Israelites were expecting Elijah to come from Heaven and prepare the way. The Encyclopedia Britannica speaks about how Israel looks at this event:
The fifth ceremonial cup of wine poured during the family Seder dinner on Passover (Pesaḥ). It is left untouched in honor of Elijah, who, according to tradition, will arrive one day as an unknown guest to herald the advent of the Messiah. During the Seder dinner, biblical verses are read while the door is briefly opened to welcome Elijah, who, it is further said, will resolve all controversial questions connected with the Law.
God’s people were so focused on the fact that “Elijah” would be preparing the way for the Messiah’s reign that they forgot one simple, undeniable fact: God is always the same. He never changes.