“Children of God” was understood by many in ancient Israel to refer to the human bloodline of a chosen people.  A true child of God is not about any national, ethnic or family bloodline.  It is not even about belonging to the right religion.  When John said the the children of God are born “not of natural descent” we see hope for all.  In this statement is a promise of salvation to Gentiles.  Whosoever will may be born of God by receiving Christ and believing in His name.   

“Yet to all who received him, to those who believed in his name, he gave the right to become children of God– children born not of natural descent, nor of human decision or a husband’s will, but born of God.” John 1:12-13 (NIV)