Serious question. Can I, due to personal beliefs, not serve cakes to Black people. Can I say black people are not allowed to purchase my cakes.

Can I say biological born males are only allowed to buy my cakes?

Can I say only Asians over 70 years old are allowed to buy my cakes?

What about if I replace the word cake with insulin? I all for freedom of religion and business but there is a line to be crossed and where is that line?