Sentence:  This means that the antennae of the congregation are extended into the community , picking up the wave lengths of those who will fit into the social and economic level of the congregation ; the mission of the church is actually a process of informal <WSD>co-optation</WSD> ; the lay ministry is a means to recruit like-minded people who will strengthen the social class nucleus of the congregation . 
Meaning of the word marked with <WSD> tags:  the selection of a new member (usually by a vote of the existing membership)