God has foreseen from eternity all the helps we need and also the helps, the graces that would move us to ask, because He treats us as free children and asks for our collaboration. We need to ask so much to obtain God's help, to do good, to persevere, as much as we need to sow in order to reap the wheat8. Without the sowing there are no ears of wheat; without petition we will not have the graces that we must receive. And as we intensify our petition, we identify our will with that of God, who is the One who truly knows our hardship and scarcity. He makes us wait at times in order to dispose us better, so that we desire those graces with more depth and fervor; at other times He rectifies our petition and grants us what we really need; finally, at other times He does not grant us what we ask for because, without perhaps realizing it, we are asking for an evil that our will has clothed with the appearance of good. A mother does not give her child a sharp knife that shines and attracts and that the little creature desires with passion. And we are like little children before God. When we ask for something that would be an evil, even if it has the appearance of good, God does as good mothers do with their younger children: he gives us other graces that will be for our benefit, even if, because of our little lights, we desire them less. Our prayer, then, must be trusting, as one who asks his father, and serene, because God knows well the needs we suffer, much better than we do ourselves.
Confidence moves us to ask with constancy, with perseverance, without ceasing, insisting again and again, with the certainty that we will receive much more and better than what we have asked for. We must insist like the importunate friend who lacked bread and like the helpless widow who cried night and day before the wicked judge. Ask and it will be given to you; seek and you will find; knock and it will be opened to you. For everyone who asks receives, and he who seeks finds, and to him who knocks it will be opened9. The same perseverance in asking increases trust and friendship with God. "And this friendship produced by petition opens the way for an even more confident supplication (...), as if, having been introduced into the divine intimacy by the first petition, we could implore with much more confidence the next time. Therefore, in the petition addressed to God, constancy, insistence, is never inopportune. On the contrary, it pleases God. This Canaanite woman is an example, which we should imitate, of constancy, although apparently the Lord did not listen to her.
In speaking of the efficacy of prayer, Jesus makes no restrictions: everyone who asks receives, because God is our Father. St. Augustine teaches that our prayer is not heard at times because we are not good, because we lack cleanliness of heart or uprightness of intention, or because we ask badly, without faith, without perseverance, without humility; or because we ask for bad things, that is, what does not suit us, what can harm us or twist our path. That is to say: prayer is not effective when it is not true prayer. "In what human business can you be given more assurance of success?": Truly I say to you, whatever you ask the Father in my name, if you have faith, he will give it to you.