re: Why do so many people on the Left hate Jews?

Marx’s famous quote that “religion is the opiate for the masses” is not interpreted within the correct context.

The emergence of pain killers in the 19th century was one of the biggest practical scientific innovations humanity had seen that century (one full of innovations). Pain was a fact of life for most of humanity. Life was tough and people lived through all sorts of pains we get resolved with medication or surgical procedures today.

So opiates were not seen through the lens of abstinence from mood altering substances that is a more modern framing. Opiates were a marvel and the industrial capacity to bring it to more people was a wonder.

Marx was lauding religion for its ability to help people live through the plights of feudal and modern society.