If we knew for certain exactly when Christ was going to come again, and when this present world would come to an end - then yes, what you say might make sense.
But we don't know - and that is the way God intended it to be. When Jesus' disciples asked Him when He would return to establish His kingdom, He answered by warning them not to be fooled by anyone who claimed to know the answer. Then 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).
Why is this? One reason, I believe, is because if we did know, we might be tempted to stop doing the work God wants us to do. In one of His parables, Jesus commended the servant who kept on working while his master was away. Then He added, "It will be good for that servant whom the master finds doing so when he returns" (Luke 12:43). May that be true of us.
At the same time, Christ's promise is clear: Some day He will come again in glory and power, and all the evil and rebellion and injustice of this present world will come to an end. That day is closer now than it has ever been before. Are you ready for that day? Make sure of your commitment to Christ - and make sure as well that if He does come during your lifetime, He will find you working and living for Him.