Now I watched when the Lamb opened one of the seven seals, and I heard one of the four living creatures say with a voice like thunder, “Come!” 2 And I looked, and behold, a white horse! And its rider had a bow, and a crown was given to him, and he came out conquering, and to conquer. (Revelation 6:1-2, ESV)
This begins the cycle of the seals. The opening of the seals displays events throughout history from Christ's first coming until the judgment. Sometimes readers of Revelation wonder if things John describes are the actual things he saw, or if they are of things John could not express in the words of his time and chose words to best describe what he saw but could not describe fully. For instance, when John tells about locusts, many think John is actually seeing a future war with Apache attack helicopters. However, I think the most logical understanding is that John is telling us exactly what God shows him in the visions. The images are highly symbolic, they are metaphors that represent things. Knowing the whole of scripture can help in understanding the symbols. Often, as with the lampstands and stars in chapter one, there is a narrative explanation of the symbols.
In this opening seal we don't have an explicit explanation. A crowned rider with a bow rides out on a white horse to conquer. Many knowledgeable interpreters have differing opinions on what this represents. Even within my theological tradition the differing opinions can be very startling. One interpreter thinks this rider is Christ going forth to conquer for the church. Another interpreter thinks this rider is anti-Christ. Quite a diverse set of opinions! No matter what the proper interpretation of the first seal, the seals show tribulation and problems. A red horse comes from the second seal that takes peace away from the earth. Famine comes with the third seal, although luxury items such as oil and wine are still found, bringing to mind that even during famine there are those who are able to avoid the effects of famine while other less fortunate suffer around them. The fourth seal reveals death.
The seals are one of the history "overlays" of Revelation that extends from the first advent to the second advent of Christ. All of these seals come by divine permission. When experience the good things and when we face trouble, that too comes from the permission of God. God is not the author of evil, and God's righteous wrath will be displayed against all who do evil. But we must remember that God does reign even when we see evil and trouble all around us. We will see that God tenderly loves his own and will make sure that nothing will ultimately harm his people.