Today, we see the faith of a woman that did not belong to God's chosen people, but trusted Jesus could cure her daughter. That mother «was a pagan, a Syrophoenician by birth, and she begged him to drive the demon out of her daughter» (Mk 7:26). Pain and love bring her to insistently beg, ignoring scorn, delays or indignities. And she gets what she is asking for, as she «went home, and she found her child lying in bed and the demon gone» (Mk 7:30).
Saint Augustine used to say that our prayers are not heard because we ask «aut mali, aut male, aut mala». “Mali”, because we are evil, for that our personal dispositions are not good, or they are bad, and we should be asking for, in the first place, to become good; “male” because we pray badly, without faith, not persevering, not humbly; “mala” because we ask for bad things, that is, things which are not good for us, things which can harm us. In the last analysis, prayer is ineffective when it is not true prayer. Therefore, «Pray. In what human venture could you have greater guarantee of success?» (Josemaria Escrivà). The Syrophenician woman is a good mother; she was begging something good («she begged him to drive the demon out of her daughter») and she begged rightly («and came and fell at his feet»).
Our Lord wants us to use insistently the petition prayer or prayer of faith. There are, indeed, other kinds of prayers —worship, salvation, prayer of thanks—, but Jesus insists very much on our often using the petition prayer.
Why? Many could be the reasons: because we need God's help to attain our greatest aim; because it expresses hope and love; because it is a clamor of faith. But there is also a motive that, perhaps, is sometimes ignored: God wants things to be a little as we like them. Thus, our petition —which is an act of freedom— along with God's omnipotent power, can contribute to make the world as God wishes and a little as we wish, too. The power of prayer is just wonderful!