Well, I Used To Be Ready...
There's the old illustration about the difference between sprinters and marathon runners. One is good at short bursts of high energy while the other is in it for the long, long haul. It takes a completely different approach and train for the 100-yard dash than it does for a race that winds around and around for over 26 miles.

As the parable of the wise and foolish virgins with their lamps and oil tells us, it is actually about the long haul with little if any bursts of energy from time to time. It is sometimes about waiting and being ready. When the moment comes and the "foolish" ones needed oil all they could say was,

"Well I was ready last night."

Found the following on The Text This Week:

The point is readiness. This is not about 2000 years of trying to whip up expectations that Jesus just might come very soon. It is about sustaining the life of faith. It is another version of Matthew's theme of elitism. Having had lamps in hand which burned well once is no guarantee they will burn in future. Having the status of being Christian, even being a light bearer, means nothing if it is not a continuing part of our being. Many who were first will be last (20:1-16). Matthew is interested in enabling people to live in a relationship with God which has continuing significance and continuing life.

The image of the closed door is harsh. It recalls similar imagery in the sermon on the mount and doubtless its use there informs its use here (7:21-23). Those who are disowned at the door there are none other than Christians who claim so much in the Lord's name, including miracles. Matthew bursts the balloons of religious enthusiasm and waffle. Not in touch with love? Then not in touch with love! Much that masqueraded in all sincerity as Christian faith then as now is what Paul would call just a clanging noise, even it had chalked up spiritual successes (see 1 Cor 13). In their different ways both Matthew and Paul put the emphasis on love as the fruit which matters.
"First Thoughts on Year A Gospel Passages in the Lectionary: Pentecost 25," William Loader, Murdoch University, Uniting Church in Australia

Yes, it is not about the bursts of enegy or enthusiasm. It's about the ongoing life of love- being ready. Which is where we get mixed up, I am afraid. We worry more about how our worship or Sunday School or Bible study "looks." We worry about the energy when the question is, are we ready? Are we working on things that don't matter in the Kingdom and therefore wasting our energy- our spiritual oil?

These are not easy questions and we each struggle in our own ways. We need worship and study to keep our spiritual lives fresh and filled with oil. But it is not the oil that is important. It is important to have it- but to use it for the work f being God's people.