I do understand but I am unable to understand why you reject the creeds of Abraham as explained in the Quran and accept creeds from our ancestors.
The natural laws of the heavens and the earth= God
Inspiration with Guidance of God= way of life authorised by God
Both the above are necessary for mankind to evolve, I get it, but why do you not use the complete and final Guidance of Allah, the Quran, to see what we have to do?
You lauded circumcision as an ancestral creed of Abraham when it is not in the Quran so is not a requirement to perform either as a natural law or as inspired guidance. If you make the creeds of Abraham what our ancestors have given us, then you have to go against the Quran. If you follow creeds of the Quran, no such problem occurs.