There is a natural assumption that building community decreases missional activity or that increasing missional activity decreases the prospects of community.
In Christ, our fellowship with one another must include both community with one another and common acts of service, love, and mercy toward others. Without both mission to others and fellowship with one another, we do not actually have community in Christ.
Fellowship with one another in Christ leads to mission. Missional activities with one another in Christ builds community. The two (community and mission) go together.
The church is both gathered by God (into community) and sent by God (into the world). We can’t have one without the other and still be God’s people in Christ.
So, what should a group of believers do if they realize that they are focusing all (or most) of their energies, resources, and times on themselves and are not reaching out to others? What should a group of Jesus’ disciples do if they realize that they are reaching out to others, but they are not building community among themselves?