Jesus clearly taught that someday He will return to earth to set up His Kingdom - but He also said that the exact time of His return is hidden from us. He said, "No one knows about that day or hour, not even the angels in heaven, nor the Son, but only the Father" (Mark 13:32).
Unfortunately, over the centuries Jesus' warning hasn't kept people from speculating about the date of Christ's return. You may have read about people who believed they knew when Christ was coming, and even sold everything they owned so they would be ready - only to be proved wrong. From time to time, groups also have appeared who claim Christ has already secretly come - although the Bible clearly says that "At that time men will see the Son of Man coming in clouds with great power and glory" (Mark 13:26).
At the same time, the Bible does teach that certain events must take place before Christ returns - and many Bible scholars believe these are already happening. I often think, for example, of Jesus' statement that the gospel "will be preached in the whole world ... and then the end will come" (Matthew 24:14).
The real question, however, is this: Are you ready for Christ's return? You can be, by turning to Him in repentance and faith and committing your life to Him. Don't let another day go by without having Christ in your heart.