Sentence:  The identification of the basic unit of religious organization - the parish or congregation - with a residential area <WSD>is</WSD> self defeating in a modern metropolis , for it simply means the closing of an iron trap on the outreach of the Christian fellowship and the transmutation of mission to co-optation . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)