I don't believe we can "lose our soul" because what can it be that lasts after death, except the soul? - not the body, the brain architecture or anything stored in it, or the etheric body. If there is any truth whatsoever to the belief in afterlife or reincarnation, at least that can be meaningfully described as "YOU living another life," then YOU can only be a soul. You can't lose or give away your most fundamental self, like losing your car. If it were otherwise, if the soul was a possession not inherently part of me, that gets transferred to another person in its next life, why do I care about that?

If you screw up badly enough (deliberately harming others) your soul might spend a lot of time in a bad situation, but then that would be YOUR fate.