He did not look back. Forgetting what is behind and straining toward what is ahead, I press on toward the goal to win the prize for which God has called me heavenward in Christ Jesus. Lot's wife looked back and it destroyed her. Sodom will petrify your spiritual life. She became petrified with fear, and was petrified into a salt statue.
Salt is a symbol of lifelessness.
Nothing grows in salt. Lot's wife was spiritually dead before she became physically anesthetized. In looking back she disqualified herself for heaven. You can't look back. That's not the direction we want to look.