Parable of the ten virgins (Matthew 25:1-13)

All the virgins (those betrothed) were called out - to separate themselves from everyone but Jesus, the bridegroom, and to "ready themselves" for His return for them. All had the proper clothing and lamps filled with oil. But the bridegroom came at a time they did not expect - they were all sleeping.

The five wise virgins were faithful to "maintain their readiness" at all times and being filled with the Spirit they were taken away (out) to be with Him. The foolish ones did not maintain their "readiness" and therefore were caught by surprise and left out.

They were told to go and buy oil (the Spirit) to get ready and maintain (be faithful) once again - for what's coming next.... (Great Tribulation) In other words, Now they will have to pay a price to enter in - but this time not as the bride of Christ.