Tzitzit and Holiness By Rabbi Saul J. Berman

The selection of the parsha of tzitzit for this purpose is motivated by the underlying purpose of this mitzvah - to remind us of the way in which all of the mitzvot of the Torah empower us to achieve holiness in our lives.

http://www.yctorah.org/component/option,com_docman/task,doc_view/gid,337/