The family was God's idea.  It was not a construct of man.  It didn't just evolve from two people. God created it on purpose and for a purpose.  It was God's design to have all of us to be in family.  Why?  Because there is power in family.  Unfortunately that power can be good and/or bad.  Not everyone has good families.  In the U.S. the normal family is blended because of divorce and/or widow or widowers.  Regardless of what the state of your family is, God has a purpose for it and you can pass a legacy on that will affect generations and change the world in the process.