Here is a prayer I pray every time I have to lead worship (which is not that often). The prayer illustrates what I was trying to get at earlier today, in the first afternoon session, namely that even superb planning can never be a guarantee that the Spirit will not need to cause a mess within our oh-so-carefully-planned liturgies. Here is my prayer:
Holy Spirit, lead this liturgy,
through me, wherever possible
against me, wherever necessary
beyond me, always.