The full quote
The context: OPIUM in the 1800s was viewed as a MEDICINE... much like MEDICINAL marijuana is used today. A salve for the soul.
However, in the years after Marx, his quote about religion being the "opium of the masses" was interpreted in a completely different way. It was viewed as something to BE DESTROYED / OPPOSED / RIDICULED because it pure DELUSION and DESTRUCTION. Marx had a different context for it.
Besides, any society based on REAL atheism will quickly fall apart because, interestingly enough, any conception of MORALITY hinges on acceptance of a PRIOR AUTHORITY... Real atheism has no space for concepts like EVIL. It's every person for himself.
Prove me wrong, bruhs!