Final answer:
The Social Gospel Movement was a religious movement focusing on solving social issues such as poverty by applying Christian ethics, emphasizing charity, justice, and community service.
Step-by-step explanation:
The religious movement that preached salvation through serving the poor was the Social Gospel Movement. This movement emerged in the early twentieth century with the goal of applying Christian principles to social issues. Advocates of the Social Gospel believed in the importance of addressing poverty, income inequality, crime, and child labor. It was influenced by the ideas of Charles Sheldon, who prompted followers with the question "What would Jesus do?" Through the settlement movement, young reformers provided social services by living among the impoverished. Organizations like the Salvation Army, YMCA, and YWCA became more prominent because of their charitable works. Moreover, the movement saw figures like Reverend Washington Gladden encouraging churches to focus on social improvements and benevolence alongside traditional religious teachings.