The virgins are the church ofcourse. The wise ones are the church or the body of believers who live wisely in this wicked world and work out their salvation with fear and trembling. They walk by the spirit (oil). They love the bridegroom (Jesus) and stay in wait for him. They live as citizens of heaven.
The foolish ones in contrast although christians, yet fail to live up to the calling. They forget the binding they will have with the bridegroom (Christ), they lack a love realtionship with the bridegroom instead they love the world and the cares and things of the world (sleep). They walk according to their flesh rather than the Holy Spirit indwelling in their hearts. Lukewarmness, worldliness,Shallowness and Immaturity is the characteristics of the foolish ones. They are unprepared for the marriage with the bridegroom. Hence they are left behind and only the wise ones are joined to the bridegroom.
The Bible says the Lord is preparing the bride (Eph 5:27 KJV) That he might present it to himself a glorious church, not having spot, or wrinkle, or any such thing; but that it should be holy and without blemish.
If the believer is unprepared he will not be raptured but go through the process of refining in the tribulation. These two points must be kept clearly in mind: 1) the kingdom is a reward to the overcoming believers, and 2) rapture requires the maturity of the overcomers.