I and others have spoken often of Pope Benedict as a superb homilist and preacher. To my mind one of the marks of this is his raising of questions in the course of his presentation.So, in the homily at the closing Eucharist in Sydney he asks: "But what is the 'power' of the Holy Spirit?" In developing his response, he says:

Yet this power, the grace of the Spirit, is not something we can merit or achieve, but only receive as pure gift. Gods love can only unleash its power when it is allowed to change us from within. We have to let it break through the hard crust of our indifference, our spiritual weariness, our blind conformity to the spirit of this age. Only then can we let it ignite our imagination and shape our deepest desires. That is why prayer is so important: daily prayer, private prayer in the quiet of our hearts and before the Blessed Sacrament, and liturgical prayer in the heart of the Church. Prayer is pure receptivity to Gods grace, love in action, communion with the Spirit who dwells within us, leading us, through Jesus, in the Church, to our heavenly Father. In the power of his Spirit, Jesus is always present in our hearts, quietly waiting for us to be still with him, to hear his voice, to abide in his love, and to receive power from on high, enabling us to be salt and light for our world.

On a related note: in the translation from Romans in today's Eucharist it says: "we do not know how to pray as we ought." Joseph Fitzmyer (and others) think that the more accurate translation is: "we do not know for what we should pray."I find the second alternative more suggestive and challenging.