If the Holy Spirit – God's way of being with us, working through us, and speaking to us – is the way in which continuity is maintained between the life of Jesus and the life of Jesus' community, prayer is the primary way in which the community actively receives and participates in that presence and working and speaking. Prayer is our way of being attentively present to God who is present to us in the Holy Spirit.
Prayer begins when God addresses us. First God speaks; our response, our answer, is our prayer. This is basic to understanding the practice of prayer; we never initiate prayer, even though we think we do. Something has happened. Someone has spoken to us, before we open our mouths, whether we remember or are aware of it or not. Just as we learn to speak our mother tongue by first being immersed in the language of our mothers and fathers, siblings and others, so we learn prayer in response to what is being said to us, over and over, by the Holy Spirit in Scripture and song, in story and sermon, in heart-whispers and bold witness.
In Luke's Gospel, five prayers articulate a language of listening and believing,
a language of receptive and responsive participation as God speaks the life of Jesus and the Jesus community into existence. They have been installed as basic elements in our life together, keeping us attentive and responsive to the Holy Spirit in and among us through the practice of prayer.
So this morning we pray the second of these five prayers – Mary's response to the angel Gabriel's message that she was to give birth to the Son of God!  Known as the Magnificat, or the “Song of Mary,” it is a canticle (song) that echoes a number of Old Testament passages (see 1 Samuel 2:1-10).
Mary's prayer takes us into a large, extensive world of God's promised word in the process of fulfillment. It is a world large with creation and wonder, history and salvation. Prayer enlarges our imagination and makes us grateful, joyful participants in what has been and is yet to come.1]

Eugene Peterson,  Christ Plays in Ten Thousand Places pp. 272-276.