I've just been reminded by my reading through Exodus that the fundamental issue of holiness is not behaviour but identity. Holiness is much more than my actions - it is where my heart is directed. It is about the rooting of my identity in the LORD. It is about being devoted to Someone in all my affections, thoughts and intentions.
Now, taking this to be the case, one can see that holiness is the gospel answer to our postmodern fragmented identities (who am I? how am I to live? where am I to live? what role am I to fulfil?). Devotion to the One God is the unifying factor for my identity - my roles and values and aspirations. My self becomes rooted in Someone greater than me - which is what I really need. Unholiness is, on the other hand, a disunifying force in me and ultimately becomes self-destructive. As we grow in holiness so we become more unified, clearer people. The various parts of us come together and we learn who we are because we know who the Lord is. It would therefore seem that holiness is the solution to many of our modern ills. Wholeness and holiness hang together.