But as many as received Him, to them He gave the right to become children of God, even to those who believe in His name, who were born not of blood, nor of the will of the flesh, nor of the will of man, but of God." John 1:9-13 (NAS)
This is a beautiful passage which us people from different nations are able to claim we are children of God.
The chosen people of God (Descendents of Abraham) believed that they are the children of God as through Abraham and all blessings of God are to them alone for quite some time.
But as in John 3:16 "whosoever believes in him" no matter what caste, color, creed or religion its everyone in this world. The same applies in this word where we have this wonderful promise in this verse that whoever believes/receives/ accepts Christ into their hearts, they get the rights to become children of God. We have the right to call him 'Abba Father' Amen.
Some commentaries on this topic can be seen here




An old preacher was dying. He sent a message for an IRS agent and his Lawyer, both church members, to come to his home. When they arrived, they were ushered up to his bedroom. As they entered the room, the preacher held out his hands and motioned for them to sit on each side of the bed. The preacher grasped their hands, sighed contentedly, smiled and stared at the ceiling. For a time, no one said anything. Both the IRS agent and Lawyer were touched and flattered that the old preacher would ask them to be with him during his final moment. They were also puzzled; the preacher had never given them any indication that he particularly liked either of them. They both remembered his many long, uncomfortable sermons about greed, covetousness and their avaricious behavior that made them squirm in their seats. Finally, the lawyer said, "Preacher, why did you ask the two of us to come?"