Jesus made it clear that some day He will come again to establish His authority over the whole world -- and this should give us great hope, no matter how gloomy or frightening the headlines may be. He declared, "When the Son of Man comes in his glory, and all the angels with him, he will sit on his throne in heavenly glory" (Matthew 25:31).
But you're right: Jesus warned us not to try to predict exactly when this will happen. Over the centuries, many people have ignored this and claimed to know exactly when Jesus was coming -- but without exception they were proven wrong. Jesus 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).
However, Jesus did tell us that certain things must happen before He returns -- and these are like signposts pointing to His coming. For example, He told us that before He comes again, the Gospel must be preached to the whole world, and only then would the present age come to an end (see Mark 13:10). And surely this is coming true today, through new technologies that can reach almost every corner of the earth with the Gospel!
The real issue, however, is this: Are you ready for His coming? Even if His coming is delayed, are you ready to meet Him -- as you will some day? Make sure of your salvation by turning to Christ and by faith trusting Him as your Lord and Savior today.