Working Out Our Own Salvation

We have been asked to give a brief dissertation on the text found in Philippians 2:12, 13. No motivation was given to signify the reason for this request. We are assuming that it was more than to give an old retired minister something to do. Was it perhaps because it appears on the surface that this text seems to contradict the general tenor of the preaching in our churches that salvation is of the Lord, and that it is entirely His work from beginning to end? Or, to put it a bit differently: if...