Complex sentence: While the foolish virgins go to buy more oil, the bridegroom then comes and the wise virgins (who are ready at that time) go into the marriage feast with him, and the door is shut.
Split into simpler sentences: While the foolish virgins go to buy more oil, the bridegroom then comes. The wise virgins (who are ready at that time) go into the marriage feast with him and the door is shut.