Soul and morality

Hello Rabbi,
I saw that the rabbi avoided seeing the argument from the existence of a soul as proof of God. [At the basis of the need for a soul is mental emotion and free choice] because it can be argued that the soul is ancient and does not have a Creator, etc., etc.
So why does the idea of ​​morality that the Rabbi presents in the book actually purify the Creator? It is also possible that it is ancient, etc. So the existence of the idea of ​​morality is not superior to the existence of the soul in relation to the proofs of God.
For some reason, this does not mean that the words of the rabbi see a difference between a morality that is refined by the legislator and a soul that is not refined by the legislator.
And I asked her why?