In the New Testament, God’s people are very seldom referred to by the title Christians, or even believers. The most common title used is brothers, emphasizing membership in one spiritual family. As Paul wrote in Ephesians 2:18, “For through Him [Jesus Christ] we both [Jews and Gentiles] have access by one Spirit to the Father.” Notice that all three persons of the Godhead are represented here. Through Jesus the Son, we have access to the Father by one Spirit.
The next verse reveals the wondrous result: “Now, therefore [because we have access to the Father], you are no longer strangers and foreigners, but fellow citizens with the saints and members of the household of God” (verse 19). The word “household” would be best represented in contemporary English by the word family. Because Christ has gained us access to the Father, we have become members of God’s family.
The composition of God’s family is determined by each member’s relationship with the Father. In New Testament Greek, there is a very close similarity between the words father and family. The word for “father” is pater; the word for “family” is patria, which is derived from pater. This relationship is brought out clearly in Paul’s prayer:
For this reason I bow my knees to the Father of our Lord Jesus Christ, from whom the whole family in heaven and earth is named. (Ephesians 3:14–15)
There is a direct play here on the words “Father” and “family.” From God the Father (pater), the whole family (patria) in heaven and earth is named. Family comes from fatherhood. Having God as our Father makes us members of His family.