John sees two witnesses, who are the two lampstands and two olive trees that stand before the Lord of the earth. These two witnesses bring testimony of Jesus and His power to reveal Him before the nations for 1260 days. However, the beast from the bottomless pit conquers and kills them. After lying in the streets of Jerusalem for 3-and-a-half days, they are risen to life as Jesus calls them up to heaven.
Many have wondered who the two witnesses are. Are they two individuals, such as Old Testament figures brought back? Are the two witnesses somehow a representation of the whole Body of Christ? Or both?
In any case, it is a call to the church for faith and endurance during times of tribulation, and an encouragement of our duty to continue giving the testimony of Jesus until He returns.