Revelation 11 speaks of two witnesses who will preach in Jerusalem in the Last Days. Those two witnesses are not identified by name. Many Bible commentators believe they will be Moses and Elijah. That makes sense since Moses represents the law and Elijah the prophets. If it is not Moses and Elijah, then we don’t know for certain who it will be. They will preach for 1260 days until the Beast (also known as the Antichrist) kills them. Their bodies will lie in the street for 3 1/2 day while the evil world gloats. Then they will be resurrected and taken to heaven in a startling display of God’s power and his approval of their bold witness to the truth.
J. Hampton Keathley III has a fine exposition of this passage called The Temple, Two Witnesses, and the Seventh Trumpet. He says the two witnesses are not literally Moses and Elijah but are “two exceptional men whom God will raise up in the Tribulation.” They will come in the spirit and power of Moses and Elijah. That interpretation makes good sense to me.