Sentence:  The expense of this type of organization in religious life , when one recalls the number of city churches which deteriorated beyond repair before being abandoned , raises fundamental questions about the principle of Protestant survival in a mobile society ; nonetheless , the prevalence of economic integration in congregations illumines the nature of the Protestant <WSD>development</WSD> . 
Meaning of the word marked with <WSD> tags:  a process in which something passes by degrees to a different stage (especially a more advanced or mature stage)