Certainly, it is a symbol of the attractions of the past. Sometimes our emotional nature cannot resist indulging in nostalgia regarding the past, even though that past was negative. We are often adhered not only to good and happy but also to misfortunes of our life. Someone has broken our heart, and has hurt us, we can spend all our life to searching for someone to blame. It is familiar to all. For Lot's wife, that attachment to the past outweighed her confidence in the future. And her looking back spoke an inclination to go back to the world.
Hamo Thornycroft "Lot's Wife"I can treat this history only from my subjective point of view. Understanding these cities, Sodom and Gomorrah, as a lowest states of consciousness, I should move only forward or upwards. Otherwise I get to a trap of doubt, uncertainty, and possibilities to fall downwards again. It's a nature of mind - to cling for known and to be afraid of the unknown. And the Lot's wife is our body, adhered to physical world. When the mind follows a body, it cannot return completely nor journey with the spirit, and freezes as pillar of salt.
It is possible to understand this history much simply but not less truly. In short, our doubt - whether one is doing right or wrong - is the enemy of faith. While faith leads to the destination, doubt pulls back. There are going to be times in our lives when we have to let go and move on no matter how deeply committed we have been to our way of life, to our job, to our own home, to all that we considered so important. It's time to turn our head from the past. If we have begun our travel, we cannot return. It is not our will. Therefore, when He tells us to not look back, we must trust. There really is no other way.