Since I will be visiting the Greek island of Patmos, where St. John wrote Revelation, in two weeks, I thought this would be a good time to look at that book of the Bible again.  Specifically, the four horsemen, probably the most studied symbols in that book.  There are a number of interpretations of these symbols and exactly what they will bring in the end times.  
    The red horse with the rider brandishing a sword is interpreted as a bringer of war.   There is little disagreement on that one.  But what war?  Between who?  On that, there are differences.
    The black horse and it's rider carrying scales is interpreted as the bringer of famine.  That too is generally agreed upon.  
    The white horse and the pale horse are not so easily interpreted.  For the white horse who's rider caries a bow and arrow and has a gold crown, there are two common interpretations.  Since white is generally a symbol of purity or light, and Jesus is sometimes depicted wearing a crown in Heaven, this horseman is often interpreted as Jesus or Christ.  Others, however, point out that since the other horsemen are bringers of evil, this one should be as well, so they interpret this rider as the anti-Christ pretending to be all goodness and light when he isn't.  
    The pale horse has also found multiple interpretations but the most common is that he brings pestilence, disease, a great plague.
    One thing that I think helps in interpreting them is looking at them in sequence, not just individually.   Also, if you accept that we are in the end times now, and that the end times lasts for centuries, not just a few years, you can form a better interpretation, so here is mine.
    I believe the white horse represents materialism and is ridden by the anti-Christ.  Materialism is the first plague or tribulation because it has turned people away from spiritual endeavors so they will concentrate on there physical existence allowing there spirit and soul to become very week.  The result is that many don't even believe in God or a spiritual world anymore.  And, since rampant materialism inevitable leads to war, the red horse and the warrior riding it follows.  And there can be no doubt that the last hundred years has been an unprecedented time of war.  The black horse and rider represents both famine and greed which creates famine when the greedy take more than their fair share of everything.  Of course, natural disasters will happen to make the famine even worse.  The pale horse and rider I think does represent disease and plague but what plague?  I think it represents two kinds of plague.  A plague on the physical level that will cause the death of many and also a spiritual plague as the millions who have turned away from God become spiritually weak and there spirits become tainted by the forces of darkness.