Obviously, we do not always receive what we ask for in prayer. Every child and every adult knows this. We even often recognize that this is a good thing, as in the Garth Brooks lyric, "Sometimes I thank God for unanswered prayers" (the caveat regarding that lyric would be that not receiving what we request does not exactly mean being "unanswered"). Sunday's Mass readings, however, include the story of Moses' prayer for Israel's success in battle, and also St. Luke's account of Jesus' words about perseverance in prayer. How are we to understand the very strong indication that these readings give us about the power of prayer?
We should perhaps pay attention to Jesus' words at the end of the Gospel reading: "But when the Son of Man comes, will he find faith on earth?" What does this have to do with the message about prayer? It could be that Jesus is asking whether there will be people faithful enough to persevere in prayer. But I think that he is also suggesting the need for faith to inform the content of our prayer, and to inform our interpretation of God's "answer" to our prayer.
Jesus speaks of "the rights of [God's] chosen ones." But faith is the foundation of that relationship with God in which we are his, and in which we know what to ask for as our "rights," what will be truly and eternally to our benefit as God's people. Jesus also speaks of "justice ... done ... speedily." But faith tells us that "speedily" does not necessarily mean, say, "instantaneously," or "in this life" - that heaven really will come quickly for the righteous and that once we are there, in perfect happiness, it will not seem as if we had to endure injustice for any significant length of time.
Sunday's second reading includes St. Paul's words about the importance of Scripture. We believe, in fact, that all of Scripture has God as its author, so that it transmits perfectly - exactly as he wills - his self-disclosure through interventions in human history, culminating in the sending of his Son. And this is not unrelated to the point about faith and prayer. As Paul suggests, Scripture (together with Tradition, interpreted with the authoritative guidance of the Church's Magisterium) is a key starting point for our faith. It is especially by living a life of devout attention to Scripture that we will grow in faith and thus also in tireless and fruitful prayer.
May God grant us to be close to him in faith, in the reading of Scripture and in prayer, in this life, and to be perfectly with him in eternity.