The Two Witnesses are two human beings who will be given extraordinary power just before Christ's return. They will give one final warning to this world.
The book of Hebrews systematically proves Christ's superiority to patriarchs, prophets, the Levitical Priesthood, and angels, establishing His credentials.
The prophets and the religious leaders bear the greatest blame for the destruction by providing a quasi-religion and not teaching the Law of God.
The events in Matthew 24 parallel the six seals of Revelation 6 and the seventh seal of Revelation 7, showing a definite chronological progression.