So for a soul to be immortal it has always existed? I don't think that is Christian doctrine. Sounds more like some sort of Eastern reincarnation dogma. Or possibly Scientology or Mormon.
The soul is created at the moment of birth, as distinct from the body which is formed and passed genetically and grows within the womb.
There is association with perceptions between body and soul, but too many phenomenon of perceptions in the soul, which are not associated with the body, to identify the body as the soul.
The issue is a classic Creation vs Seminal interpretation of the origin of human life.
Except that the LORD personally proclaims this in Jeremiah 1:5. This is Jewish doctrine, which was then inherited into Christianity.
It is sad, really, the author and poster make good points, but by contradicting an irrefutable Jewish and Christian law regarding murder, he elevates the legitimacy of the other myths that he tries to debunk.