No, the foolish virgins weren't Christians. They weren't allowed into the wedding banquet which symbolizes the wedding feast of Jesus and the church.
Everyone who's saved already has the Holy Spirit. We're sealed by the Holy Spirit on our day of redemption. We have more of the Spirit the more we mature in Christ.
In the parable, the foolish virgins are told something very similar to what the wicked are told by Jesus.
(Matthew 25:11-12 NIV) "Later the others also came. 'Sir! Sir!' they said. 'Open the door for us!' {12} "But he replied, 'I tell you the truth, I don't know you.'
(Matthew 7:22-23 NIV) Many will say to me on that day, 'Lord, Lord, did we not prophesy in your name, and in your name drive out demons and perform many miracles?' {23} Then I will tell them plainly, 'I never knew you. Away from me, you evildoers!'