Those who are in Christ have experienced a profound transition from a state of enmity and strangeness to the condition of being members of the same family. Here Paul speaks further of the change in the believer's status and position. The emphasis here is that there is no way to revert to a former state of being or condition. Jesus Christ does away with zenophobia, the fear of strangers.
Strangers become family members, fellow citizens.
Those who are outside are admitted to fellowship. In a Greek inscription, this word was used to refer to a licensed practitioner who, although he was a foreigner, was permitted to stay in the community to practice his trade. Describing believers as citizens was an effective way to describe the position in God's kingdom that Jews and Gentiles now share equally. Here it speaks figuratively of members of the household of faith in Jesus Christ. What follows is another view of the great doctrine of Edification.