The burning of bridges signifies a deliberate act of severing ties with the past, making a conscious choice not to go back.
If we want to get rid of sin in our lives we have to burn bridges that lead to that sin, to deliberately and decisively cut off all access to a particular temptation or sinful behavior. essentially making it impossible to return to that path by removing all means to engage with that again.
A drug addict will often return to the same town, the same group of “friends” that they did drugs with after being rehabilitated which often causes them to relapse and start using drugs again. They have to break all ties if they want to have a successful recovery.
This bridge represents a pathway or connection to a sinful action, like a bad habit, a certain environment, or even a relationship that enables negative behavior.
In spirituality context, the burning of a bridge is used to describe the process of repentance, where someone actively removes themselves from the influence of sin to fully dedicate themselves to a life of faith.
Of someone recognizes that a certain friend is leading them towards harmful behavior, “burning the bridge” could mean ending the friendship to protect their own well-being.
If someone decides to adopt a healthier lifestyle, they might “burn the bridge” by removing unhealthy foods from their home and committing to a new exercise routine.
Old acquaintances, old haunts, and old habits are the bridges that we must burn in order to start down and remain on a narrow path. (Matthew 16:24, 19:29, Colossians 3:5).

From Pity to Praise 