Abstract from The Introduction to Contribution To The Critique Of Hegel’s Philosophy Of Right

To abolish religion as the illusory happiness of the people is to demand their real happiness. The demand to give up illusions about the existing state of affairs is the demand to give up a state of affairs which needs illusions. The criticism of religion is therefore in embryo the criticism of the vale of tears, the halo of which is religion.

…

The weapon of criticism cannot, of course, replace criticism by weapons, material force must be overthrown by material force; but theory also becomes a material force as soon as it has gripped the masses. Theory is capable of gripping the masses as soon as it demonstrates ad hominem, and it demonstrates ad hominem as soon as it becomes radical. To be radical is to grasp the root of the matter. But for man the root is man himself. The evident proof of the radicalism of German theory, and hence of its practical energy, is that it proceeds from a resolute positive abolition of religion. The criticism of religion ends with the teaching that man is the highest being for man, hence with the categorical imperative to overthrow all relations in which man is a debased, enslaved forsaken, despicable being…..