Passage: Ephesians 1.1-2 (ESV Bible Online).

“by the will of God”

Obeying God is obviously important to Paul.  He will later exhort some of his readers, or those listening to his letter read out loud, that they do “the will of God from the heart” (Ephesians 6.6).  So it would be natural, in reading this phrase, to think that Paul is simply pointing out that his commission as King Jesus’ ambassador is backed by divine authority.

However, Paul seems to be saying something more here.  Consider what Paul says in the next few sentences,

he predestined us for adoption through Jesus Christ, according to the purpose of his will, to the praise of his glorious grace, with which he has blessed us in the Beloved. In him we have redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace, which he lavished upon us, in all wisdom and insight making known to us the mystery of his will, according to his purpose, which he set forth in Christ as a plan for the fullness of time, to unite all things in him, things in heaven and things on earth.  In him we have obtained an inheritance, having been predestined according to the purpose of him who works all things according to the counsel of his will, so that we who were the first to hope in Christ might be to the praise of his glory (1.5- 12; emphasis added).

So when Paul announces his Apostleship “through the will of God,” he is saying that God appointed him to the office in order to fulfill His plan to save the world.  Jesus’ accomplishments alone are not enough.  It was and is essential to God’s purpose that the message of Jesus be announced to all the world.  As we will see, Paul views Jesus himself to be traveling, working, and speaking through his servants (c.f. Ephesians 2.17).