Ephesians 3:14-15

For this reason I bow my knees before the Father, from whom every family in heaven and on earth is named,

-Ephesians 3:14-15

This verse begins with the words, "For this reason".  This is the same as the beginning of this chapter.  Paul seems to be recalling back to the same thing he did at the beginning of the chapter.  I guess you could argue that it's pretty much what he's been talking about all along.  He is referring back to what he spoke about in chapter two about God saving us by grace through faith and breaking down the dividing wall of hostility by becoming our peace.  So, because of this, Paul prays to God on behalf of his readers.

Paul goes off on a bit of a tangent.  He is praying to the father, about whom he says "from whom every family in heaven and on earth is named".  NLT puts it this way, "the Creator of everything in heaven and on earth" and AMP puts it this way, "from whom every family in heaven and on earth derives its name [God—the first and ultimate Father]".  God is the father of us all.  He has created each and every one of us.  This is the one whom Paul prays to on behalf of his readers.