As the founder of Marxist theory, Engels’ profound remarks pointed directly at the core issue of society-class struggle. Engels once emphasized: "Everything we do is ultimately about class struggle." This showed his firm stance on social change and the liberation of workers.

The core views of Marxism are based on the theory of class struggle, which Engels discussed in depth. He revealed that class struggle stems from changes in the mode of production. He believed that the exploitative nature of capitalist society stems from the capitalists' possession of workers' surplus value. This inequality leads to workers being oppressed, and capitalists use this to accumulate wealth.

Engels’s criticism of capitalism was based on its exploitative nature of working people. He firmly believes that socialist revolution is a historical necessity. The proletariat needs to overthrow the bourgeoisie through class struggle, achieve the goal of communism, and liberate the people suppressed by capitalism.

Engels’ theory emphasized the inevitability of history and continuous progress. He advocated seizing opportunities for change and promoting the development of social productivity. His ideas went beyond simple political changes and advocated comprehensive social progress and the improvement of productivity, which is the core of the socialist revolution.

In summary, Engels’s famous sayings, with their depth and breadth, not only reveal the practical significance of class struggle, but also provide theoretical guidance for us to understand the shortcomings of the capitalist system and seek the road to socialism. His ideological legacy has had a profound impact on the liberation of the working class and working people, and is an indispensable part of the treasure trove of Marxist theory.