I came up with the concept for this one when I was sitting by a window at my technical school and watching all the people in their vehicles scurrying around town to complete their duties and errands. The topic I decided to center around was materialism, the pointlessness of trying to achieve prosperity on this crooked earth, and the useless way of life this world has adapted to.
Money. Vanity. None of these artificial earthly things will bring us true happiness. We cannot gain true joy and happiness from mere earthly deeds, but through sacrifices we make that comes from the heart. All of these worthless things will be destroyed when our Creator puts His ultimate plan into action. The flame I mention in the second bridge is meant to represent both God and his plan described in the book of Revelation.
In the end, all this work us humans are performing on this earth is useless. We will have gained it all for no reason other than our own pleasure. Ineffectively, we are working for a better life. Unavailing strife.