Some conflict theorists would deny that positive social change really occurs through religion, but others will say that the oppressed classes can sometimes use religious rhetoric to gain advantages in their conflicts with the dominant classes. Both of these interpretations could be applied, for example, to the Civil Rights Movement in the United States.
From one perspective, the Civil Rights Movement was able to use religious rhetoric to defeat the dominant classes in its time and place. The dominant class at that time was made up of white people. The dominant whites engaged in discrimination against African Americans and mistreated them in other ways. The Civil Rights Movement used Christian rhetoric as a way to gain support as they fought against white domination. They essentially turned the dominant group’s religious teachings against it.
Of course, it is also possible to argue that the Civil Rights Movement did not truly bring about meaningful social change. It could be argued that some African Americans were allowed into the dominant middle and upper classes while the masses of African Americans remain oppressed due to racial and economic factors. From this point of view, religion can appear to bring about social change, but the social change is somewhat illusory.