Josua, your idea about what the virgins' oil is: "knowledge of Gods word and understanding of Gods word through the holy spirit" makes total sense to me. I mean, we can repent in an instant, and be forgiven and cleansed by our gracious God and the blood of Christ as soon as we do, but it takes time to learn to walk in holiness. Another poster commented on this as well - yesterday, I believe.
There is still mystery in this parable, of course, but your post and the other I mentioned have given us new things to ponder as we seek to understand. Thanks!