"And when ye shall see Jerusalem compassed with armies, then know that the desolation thereof is nigh. Then let them which are in Judaea flee to the mountains; and let them which are in the midst of it depart out; and let not them that are in the countries enter thereinto."
The key to understanding Lot and his daughters is to understand that the Bible is written in parable language. For example, the above verse from Luke is describing the same situation as in Genesis 19, but is using slightly different language. Notice that the men of Sodom, in Genesis 19, compass Lot's house just as the armies compass Jerusalem in Luke 21. Angels in Lot's case are a picture of the believers' and their message, even perhaps of Christ. They arrive at evening, a picture of the time period towards the end of the church age as Christ's coming is nigh, possibly. At that time, the congregations seem to have become wicked and do not know how to do anything but mistreat or reject the true believers such as Lot and those who have come under his roof (roof is a picture of where the gospel being proclaimed). The daughters mentioned in Genesis 19 have not known man, meaning apparently that they are not saved or in Christ. They have not know Christ. The angels on the other hand have come under the roof, meaning apparently that they have come under the protection of the gospel. Notice how the true believers strike the unbelievers blind so that they cannot find the door. The door in parable terms is Christ. Remember, he is the door of the sheep. The true believers' gospel has shut the door for a period of time during which it seems that there is no salvation for those without: "And while they went to buy, the bridegroom came; and they that were ready went in with him to the marriage: and the door was shut." Notice that during this story, Lot and the true believers flee away from the fallen congregations and they flee to Christ himself. Just as Luke tells us to "flee to the mountains"; in parable language this means to flee to the Lord himself. After all, as the mountains surround Jerusalem, so the Lords surrounds his people. Fleeing to the mountains means flee to the Lord. In the heart, the true believer does not flee to institutions that have grown wicked, nor trust in a fallen congregation for salvation. Rather, the true believer flees in his heart to the Lord for help, for salvation, for safety. When Lot offers the two daughters who are apparently unconverted to Christ, to the fallen congregations, it seems to possibly be describing how those who are unsaved, the foolish virgins in the parable of the virgins, will be given over to destruction, whilst Lot (representing those who are wise) is saved.