This is a curious definition -- we would have said nonsensical, except that that would be rather judgmental -- because it does not require elements often associated with religion, such as deity, morality, world view, etc. Capitalism, homophobia, transphobia, President Obama's place of birth, and other beliefs might fit this definition. Also it requires that a person pursue their religion with enthusiasm. Many people identify themselves with a specific religion, but are not intensely engaged with their faith.
Soon after the Manifesto was published, Paris erupted in revolution to overthrow King Louis Philippe . The Manifesto played no role in this; a French translation was not published in Paris until just before the working-class June Days Uprising was crushed. Its influence in the Europe-wide revolutions of 1848 was restricted to Germany , where the Cologne-based Communist League and its newspaper Neue Rheinische Zeitung , edited by Marx, played an important role. Within a year of its establishment, in May 1849, the Zeitung was suppressed; Marx was expelled from Germany and had to seek lifelong refuge in London. In 1851, members of the Communist League's central board were arrested by the Prussian police. At their trial in Cologne 18 months later in late 1852 they were sentenced to 3–6 years' imprisonment. For Engels, the revolution was "forced into the background by the reaction that began with the defeat of the Paris workers in June 1848, and was finally excommunicated 'by law' in the conviction of the Cologne Communists in November 1852".