The Revelation of Jesus Christ, which God gave Him to show His servants—things which must shortly take place. And He sent and signified it by His angel to His servant John, Revelation 1:1
The focus of the book of Revelation is Jesus Christ and His soon coming kingdom and return. Jesus shall return for His bride and after the tribulation has finished will return to the earth to establish His kingdom for 1000 years.
The book of Revelation was a series of visions given to the Apostle John and was for the edification and strengthen of the body of Christ. At the time this was written Domitian was the emperor of Rome. The church faced intense persecution and the Lord revealed what lay ahead.
It states things which must shortly take place. Much of the events written and presented in Revelation will take place once the bride of Christ has been removed. The bride includes all those who have given their full heart to Christ and live for Him daily.
This was communicated to John by an angel sent from the Lord. We should never fear the book of Revelation but we should study it diligently as it reveals Christ ultimate victory and Satan's ultimate defeat. We should study the whole counsel of God's word and be diligent students daily. As we open our hearts and seek the Holy Spirit for greater revelation, wisdom, knowledge, and understanding the Lord shall give us eyes to see and ears to hear.