This parable sounds a little bit harsh. What happened to the Good Shepherd who opens the gate for the sheep from other folds? What about grace? I wonder if this parable is less about wise/foolish or good/bad and more about how we wait.
Do we stay alert to the continuing work of the Spirit, transforming and renewing us and those around us day by day? Are our eyes open to the needs of others? Do we hear the cry of those without a voice? Do we allow comfort and safe routines lull us into sleepy complacency? Do we expend all our energy feverishly searching for more oil (more friends, more allies, more money, more acclaim, more affirmation, etc.), while missing out on doors that Jesus might be opening for us?
In prayer, ask the Spirit to continually fill you up with everything you need to answer the invitation of Jesus.