The din is that everyone must write a personal Torah or at least help to make the writing of a Torah possible – even if you have inherited a Torah from your parents, even if your neighbour possesses a Torah, even if you live next door to a synagogue.
Though this law is meant literally, some interpret in their own way by making up their own book of rules. The Tanach recognises this when it speaks of everyone doing what is right in their own eyes. They are convinced they can do a better job than the Torah. Other philosophies become their principles, other rules their ethics. And with what result?
I answer the question with a memory. Once I worked for the Association for Jewish Youth in Britain. Amongst my tasks was organising weekend camps and seminars. On one occasion the participants wanted to compile their own Shabbat service, and I agreed.
They worked on it diligently and tried many things. I made no comment when what they finally came back with was almost identical with the Siddur. Their conclusion was that writing your own service seems to lead you back to where you came from.
In the 20th people tried many “isms”. Many still do in the 21st century. A significant record of this quest led to a book called, “The God that Failed”, about how communism let its adherents down. So did apartheid, and so did other perverted ideologies.
Likewise, people try to formulate their own ethics – racism, vandalism, sadism, selfishness, cynicism, greed… the list is endless. Writing your own rules often ruins your own life as well as others’.
Judaism said to write your own Torah. It meant the Torah of tradition. It was wise. If you look for Torah anywhere else you will eventually come back to the Torah of Moses and embrace it with your heart, soul and might.