Paul is using a metaphor to tell his Gentile readers that though God formerly did not consider them part of his people, God now considers them part of his people. (See: [[rc://en/ta/man/jit/figs-metaphor]])
# foreigners and strangers ... fellow citizens ... and members of the household
The words "foreigners" and "strangers" mean almost the same thing, so "strangers and foreigners" may be a doublet. However, Paul is contrasting "foreigners and strangers" with "fellow citizens ... and members." The word "citizens" refers to having political rights, so here "foreigners" probably refers to people living in a country not their own and having no political rights. The word "members" refers to being part of a family, so "strangers" probably refers to people who are not part of a family. (See: [[rc://en/ta/man/jit/figs-doublet]])