If we are the children of God, if we are the heirs of God, and joint-heirs with the Lord Jesus Christ, then all who believe in the Lord Jesus constitute one family. They may be scattered all over the world, may in ten thousand things differ as to the present life, and in ten thousand things have differed as to their manner of life before they were brought to the knowledge of the Lord Jesus,—may differ after their conversion as to their position in life, and in numberless ways also as to attainments in knowledge and grace; but nevertheless, as assuredly as they believe in the Lord Jesus for the salvation of their souls do they constitute one heavenly family—they are brethren. We glorify God by living as such here. In heaven we shall be together. Throughout eternity we shall be unspeakably happy, and love one another perfectly and habitually. But we are to glorify God by manifesting this love now, while on the earth, while in weakness and exposed to conflict, while the struggle is going on; now we are to be united together, and to manifest that we are one family, the heavenly family. This is the way to bring glory to God.
George Müller, Jehovah Magnified