He was ethnically Jewish, but probably not raised in Judaism given that his father converted to Lutheranism. (His grandfather was rabbi of Trier.) He solidified his atheism during his college years, when he embraced Hegelian philosophy. So not regarding himself as a Jew in any sense, it was easy for him to fall into garbage like he was uttering here, believing that getting rid of all religion would “liberate” humanity.
Marx wasn’t Lutheran either! Just the father of commie atheism!!!!
Karl Marx said, “antisemitism is the socialism of fools,” thus confirming that socialism basically repackaged the demonization, conspiracy theories, and other garbage of antisemitism.