The third chapter of Stetzer's book is the token chapter on biblical basis. These chapters in every textbook drive me crazy. It's like every person has a biblical basis for their own slant on whatever. It's like treating the Bible like a horoscope.
That being said, this chapter isn't horrible, but it's not the kind of subject matter you wake your wife up to discuss. Here's some quotes of interest:
p.38 "Until the late eighteenth century, most Protestant Christians believed that Jesus' commisions applied only to those disciples who actually heard his words."