What does Revelation 6:1 mean?
In this verse John watches as the Lamb of God opens the first of seven seals. We learn from chapter 5 that Jesus is the Lamb and He alone has the moral and legal right to open the scroll that He took from God's right hand (Revelation 5:5–7). Further, He alone is worthy to open the seven seals that kept the scroll shut.When the Lamb removes the first seal, one of the four living creatures (Revelation 4:6–8) shouts in a thunderous voice. It is a command, to the first horseman, to come forth. Revelation 6 will continue by showing that the opening of each of the first four seals is followed by a living creature's command to come. As the horsemen respond, calamitous judgments fall on the earth.
When the apostle Paul preached in Athens, he announced that God has set a day when He will judge the world in righteousness by a man whom He has appointed. Paul identified that man as the one whom God raised from the dead, meaning Jesus (Acts 17:31). During the events described in Revelation 6, the time of judgment at Jesus' hands has come.