“Then the Kingdom of Heaven will be like ten bridesmaids who took their lamps and went to meet the bridegroom. Five of them were foolish, and five were wise. The five who were foolish didn’t take enough olive oil for their lamps, but the other five were wise enough to take along extra oil. When the bridegroom was delayed, they all became drowsy and fell asleep. (Mathew 25:1–5).
Jesus, through this story, was illustrating an important truth: you can be part of the church (the bridesmaids) and only serve Him superficially (the bridesmaids who had no oil). The truly saved believer is the one who is prepared for His coming. They live for Him every day.
We could change the story to people who take tests. Some are working hard every day to learn the material. Others try to cram the night before the test. Usually, the people who consistently study get a much better education.
Are you living your life figuring you have lots of time and when you get older you will "get your act together" (i.e. you will cram)? That is a way of living that leads to destruction. Walk with Him every day. Keep your lamps full. Live with anticipation that THIS could be the day He returns to call us to Himself.