For this reason I bow my knees before the Father, from whom every family in heaven and on earth is named.” Eph 3:14-15 “
The family before us consists of all real Christians–all who have the Holy Spirit living within them–all true believers in Christ–all the saints of every age, and Church, and nation, and language. It includes the blessed company of all faithful people. It is the same as the Elect of God–the household of faith–the mystical body of Christ–the bride–the living temple–the sheep that never perish–the Church of the firstborn–the holy universal Church. All these expressions are “the family of God” only using other names.
Membership in “the family of God,” does not depend on any earthly connection. It does not come by natural birth, but by new birth. Ministers cannot impart it to their hearers. Parents cannot give it to their children. You may be born in the godliest family in the land, and enjoy the sweetest fellowship of grace that any Church can supply, and yet never belong to the family of God. To belong to it you must be born again. No one but the Holy Spirit can make you a living member of this family. It is His special function and prerogative to bring into the true Church all those who will be saved. Those who are born again are born, “not of natural descent, nor of human decision or a husband’s will, but born of God.” [John 1:13] [J.C. Ryle, “The Family of God”]”