We may be familiar with persons who somehow or other always manage to get what they want. By hook or by crook, they are determined to get it.

Often enough they do not get discouraged by what other people may say about their tiring insistence, or even by the rude manners they manifest.

We have all seen people, for example, who have no patience and still less manners when, while shopping, skip their queue and expect to be served before the other customers who were there before.

Such was more or less the case with the poor widow in today's parable. She kept bothering the judge to vindicate her cause. As a widow in the ancient Near East she is without financial resources.

Since the court of law set up each time in the open near the city gate, as was then customary, was entirely a male realm, we can picture the poor widow as a lone woman amid a noisy crowd of men.

Some clients gained access to the judge by supplying bribes through one of the clerks, insensitive to the clamour of the rest. What is more, the judge is described as one "who does not fear God", which makes the widow's situation even more painful. The only strategy available to her was persistence, by which she finally got through to the shameless judge.

St Luke in today's gospel declares that Jesus told this to show more forcefully "the necessity of praying always and not losing heart". He does somehow take the risk of parallelling God with a godless judge, because he concludes the story by saying: "If the widow wins vindication from a godless judge by persisting in her demand, how much more will your persistence get a response from your loving God?"

It may occur, of course, that some situations simply require our involvement in prayer over an extended time. The classic example of this is the prayer of St Monica, the mother of the errant young man whom the Church would eventually canonise as St Augustine.

In his Confessions, in fact, this great Doctor of the Church acknowledges that it was the persistent prayer of his mother that facilitated his adult Christian conversion.

The importance of prayer for our life as Christians is indeed great. We may even say, I suppose, that it is one of its essential elements.

Some people are discouraged because, so they say, they never get what they ask for. Others say that they do not know how to pray. Others still believe that the only kind of prayer for them is vocal prayer, which often leaves them cold and even annoyed.

Sometimes we hear people say that they do not see any need for prayer, because God already knows what we want or need. Which brings us back to St Augustine, who said: "We do not pray to inform God about our needs, because he already follows them; and yet God wants us to pray so that we may be well disposed to receive God's graces." Along these lines is what Mother Teresa has written: "Prayer enlarges the heart until it is capable of containing God's gift of himself."

Prayer is not a luxury, something we can do without, but an essential element in Christian life. The degree of our faith is the degree of our prayer, the strength of our hope is the strength of our prayer; the warmth of our charity is the warmth of our prayer. Prayer is like the air we breathe; we neither see it nor feel it. Only its absence will be immediately felt.