In answering this question, we MUST remember that it is a PARABLE!! It is not necessarily literally true but teaches an important spiritual lesson.
However, we observe several things about the foolish virgins who are distinguished ONLY by the amount of oil they possessed. Note the comments of Ellicott:
(3) Took no oil with them.—In the interpretation of the parable, the
lamp or torch is obviously the outward life of holiness by which the
disciple of Christ lets his light shine before men (Matthew 5:16), and
the “oil” is the divine grace, or more definitely, the gift of the
Holy Spirit, without which the torch first burns dimly and then
expires. The foolish virgins neglected to seek that supply, either
from the Great Giver, or through the human agencies by which He
graciously imparts it.
Note that oil is an occasional metaphor for the Holy Spirit in other places as well, Luke 4:18, Acts 10:38, 2 Cor 1:21, 22, 1 John 2:20. However, the important fact is that the possession of the oil is what permitted the five wise girls to enter the wedding and what excluded the five foolish girls.
Since both the wise and foolish virgins both had the oil (whether the gift of the Holy Spirit or not) we may deduce that they had both been introduced into the membership of God's people. We see this same idea in other places. For example, Heb 6:4-6 also teaches that some “who have once been enlightened, who have tasted the heavenly gift, who have shared in the Holy Spirit…” can fall away. Jesus taught the same idea in other parables as well -
- Jesus’ parable of the vine (John 15:1-8) says two interesting things: (a) that branches (connected to the vine of Jesus) that do not bear fruit are cut off (v2); and (b) the bearing of fruit is to prove that we are Jesus’ disciples.
- Jesus’ parable of the sower, or perhaps the parable of the soils (Matt 13:1-23, Mark 4:1-20, Luke 8:4-15) contains several classes of people (soils) who start out well in the Christian life but lose their way. The conclusion is also significant: “by their constancy bear fruit”. (Luke 8:15)
- Jesus’ parable of the banquet (Luke 14:16-24) contains a very good example of people rejecting the call (or “election”) of God as well as God having to ask some people more than once and begging them to the wedding banquet. Jesus’ conclusion is, again, significant, “not one of those men who have been invited shall taste of my banquet.” In the parallel passage of Matt 22:1-14, Jesus concludes by saying, “For many are called, but few are chosen.”
Heb 10:19-35 contains an extended passage on enduring. It contains some real gems about the possibility of losing one’s faith and confidence such as:
- V26: If we(!) deliberately keep on sinning after receiving the knowledge of the truth, no sacrifice for sins is left
- V29: How much more severely do you think someone deserves to be punished who has trampled the Son of God underfoot, who has treated as an unholy thing the blood of the covenant that sanctified them and who has insulted the Spirit of grace. This verse clearly shows that it is possible to be sanctified and subsequently lost.
- V35: Therefore, do not throw away your confidence which has a great reward.
o V36: You need to persevere so that when you have done the will of God you will receive what he has promised.
Thus, it is entirely possible that those who were once God's chosen people can decide to disconnect themselves from God's offer of salvation and be lost.
Here are more examples of this:
- Ps 69:28 contains a plea for David’s enemies to be blotted out of the book of life!
- Eze 18:21-28 also teaches that the wicked can reform and be saved, and the righteous can apostatise and be lost. Both situations are incompatible with Calvinism’s view of salvation and humanity.
- Rom 11:17-21 discusses the warning that people who had been grafted into the “olive tree” of the Christian community could be broken off if they were unfaithful.
- 1 Cor 9:27 Paul says he disciplines his body to keep it under control so that after preaching to others he does not become a castaway/disqualified. That is, Paul believed that it was possible that he could lose his way and become lost.
- 1 Cor 10:12 also contains a stern warning from Paul, “If you think you are standing firm, be careful that you don’t fall.”
- 1 Tim 6:10, For the love of money is the root of all kinds of evils. It is through this craving that some have wandered away from the faith and pierced themselves with many pangs.
- 2 Peter 2:21, “It would have been better for them not to have known the way of righteousness, than to have known it and then to turn their backs on the sacred command that was passed on to them.”
- 2 Peter 3:17 contains a very stern and sobering warning to be on guard that we do not fall from our secure position. Verse 14 contains a similar warning.