The present study is a slightly revised version of a 2005 Ph.D. dissertation, written under Prof. Loren Τ. Stuckenbruck, and submitted to the University of Durham. I wish to thank the editors of Beihefte zur Zeitschrift für die neutestamentliche Wissenschaft-James D. G. Dunn, Carl R. Holliday, Hermann Lichtenberger, Jens Schröter, Gregory E. Sterling, and Michael Wolter for accepting the work for publication.