Sentence:  He says : `` Beside the Protestant philosophy of Progress , as expressed in radical or conservative millenarianism , should be placed the doctrine of the democratic faith which affirmed it to be the duty of the destiny of the United States to assist in the creation of a better world by <WSD>keeping</WSD> lighted the beacon of democracy '' . 
Meaning of the word marked with <WSD> tags:  keep in a certain state, position, or activity; e.g., "keep clean"