Basically the article is saying that there are many definitions of the term literacy, each of which are different, and incomplete in some way. Sylvia has broken the definition down into three metaphors that when put together can become the definition of literacy, but when apart are not a complete defenition.
Literacy as a state of grace: Literacy gives intelectual meaning to a literate persons life, and fills it with knowledge of human kind.
Literacy as power: Literacy has always been used as a tool to seperate people into classes. The more elite are literate, while the poor etx are illiterate. It creates a social/economic standing.
Literacy as Adaption: Literacy allows you to adapt to regular life. It is important for jobs, going through town, grocery shopping. Basically everything you do in daily life in western culture involves literacy, and without it you will not adapt.
I think that the arrangement was such that Scribner seperated the different metaphors to teach us what they all meant seperately, but also brought it all together to conclude that one didn’t work as a deffinition alone, but only together! The invention of it is quite interesting, becuase I have never heard literacy being put in this way, but when you think about it, everything she is saying is extremely true.