Apparently you have no reason not to believe it is a soul.
But you do have good reason to believe it is a soul.
- You referred to it as a lifeforce.
- You claim it did not proceed from the material world and makes you more than physical (i.e. it is spirit).
- You believe it is the source of your love.
- It moves you.
- You claim you don't know what it is therefore you cannot rule out it is a soul.
The definition of soul is the spiritual or immaterial part of a human being or animal, regarded as immortal.
The definition of lifeforce is the spirit or energy that animates living creatures; the soul.
Are you telling me that your children have no soul?