Only God knows when He will intervene to bring an end to the world's evil and establish Christ's rule–but you can be certain it will happen. As Jesus ascended into heaven after His resurrection the angels promised, "This same Jesus, who has been taken from you into heaven, will come back" (Acts 1:11).
Although God hasn't given us an exact timetable, the Bible does tell us to be prepared for Christ's coming. When He comes again, most people will be caught off guard, thinking that this world is going to continue the same way it always has. This is why Jesus said to His disciples, "So you also must be ready, because the Son of Man will come at an hour when you do not expect him" (Matthew 24:44).
At the same time, the Bible does tell us that certain things must happen before Christ returns–signs that will point to His coming. For example, Jesus said that "this gospel of the kingdom will be preached in the whole world ... and then the end will come" (Matthew 24:14). This is happening today more than ever, through the use of the mass media and the Internet, as well as the efforts of missionaries and evangelists throughout the world.
The most important question, however, is this: Are we ready to meet Christ–either when He returns or when we face death? We can be, by turning to Him in repentance and faith, and committing our lives to Him. Has this happened in your life?