"Ask, and it will be given you; search, and you will find; knock, adn the door will be opened foryou. For everyone who asks receives, and everyone who searches finds, and for everyone who knocks, the door will be opened. Is there anyone among you who, if your child asks for bread, will give a stone? Or if the child asks for a fish, will give a snake? If you the, who are evil, know how to give good gifts to your children, how much more will your Father in heaven give good things to those who ask him!" (Matthew 7:7-11) (NRSV)
Let's start with the literary context. Jesus has challenged his followers on many fronts throughout the sermon. Even a partial list is daunting: the Beatitudes, taming the heart as well as behavior, loving enemies, meaningful prayer, laying aside materialism, discernment versus judgementalism, and the like. It seems to me that any sane person might well have asked himself or herself: "Where will I find strength and wisdom enough to begin and follow such a life's path?"
Matthew 7:7-11 addresses the matter. Jesus once again calls his followers to rely upon God. He uses active language: ask, seek, and knock. One may ask, seek and knock via prayer, but also through study, reflection, and conversation. Seeking God's way is not a passive affair!
Lots of nonense has been written over the years regarding the phrase "and it will be given you." Given the fact that Jesus did not always receive what he prayed for, we cannot accept the idea that we shall receive whatever we request. I prefer to link the phrases "will be given," "will find," and "opened to you." Here I think Jesus practiced parallelism, stacking similar phrases atop one another in order to drive home his point: God is prepared to give you what you most or really need.
That's the point of Jesus' language about human parents and their children. If a human parent (assuming a "normal" relationship) can be trusted to try and give good things to his or her children, surely God can be trusted to do so and to get it right.
My experience (and that of others) is of a God who often does not answer the question I ask but instead another question. God frequently does not give me what I seek but something else instead. As for doors, God most often does not open the one I want opened but instead leads me through another. It can be quite frustrating. Here's the thing, though: Such experiences reshape us, given time and acceptance, from self-centered urchins into adults more willing and able to flex, give of ourselves, appreciate others, and walk in faith.