This text is part of the Sermon on the Mount. To a significant extent it addresses the subject of prayer. The text must be understood in the context of the rest of of the sermon. Matthew records that Jesus has already taught about prayer (6:5-15) and other topics that have a bearing on this text (e.g., seeking God's kingdom and trusting him to meet our material needs [6:25-34]).
"Although Matthew has already offered a longer section on prayer (6:5-15), he emphasizes prayer again here. Because in the context the supreme object of 'seeking' is the kingdom (6:33) and the door to be opened is the gate of salvation (7:13; contrast Lk 11:5-13), this prayer may especially represent a prayer for God's rule (compare 6:9-10 and the prayer for empowerment by the Spirit in Lk 11:2-13)" (Keener, Matthew, commentary on Matt. 7:7-12).
A parallel passage with slight variations is Luke 11:9-13.
Principle #1: God gives us his best when we pursue it actively (vv. 7-8).
"[. . .] your Father knoweth what things ye have need of, before ye ask him" (6:8).
"[. . .] if two of you shall agree on earth as touching any thing that they shall ask, it shall be done for them of my Father which is in heaven" (18:19).
"And all things, whatsoever ye shall ask in prayer, believing, ye shall receive" (21:22).
Matthew uses the verb zeteo some 13 times. The objects being sought include the kingdom of God (6:33), pearls—as a figure of the kingdom of God (13:45), a lost sheep (18:12), and the person of Jesus—both for good and evil ends (2:13; 26:16; 28:5).
On the subject of seeking, see the following Old Testament texts, each of which calls on God's people to seek him from captivity.
"But if from thence thou shalt seek the LORD thy God, thou shalt find him, if thou seek him with all thy heart and with all thy soul" (Deut. 4:29).
"And ye shall seek me, and find me, when ye shall search for me with all your heart" (Jer. 29:13).
The text does not make explicit reference to a door or gate, but it is implied.
The action is to be persistent, as implied by the use of present tense (i.e., continuous action) verbs in the Greek.
"Now [Jesus] assured them that God welcomes prayer, and urged them to come to Him continuously and persistently. This is emphasized by the present tenses in the verbs" (Barbieri 34).
"The three present imperatives in this verse (Ask…seek…knock) are probably intended to call for a repeated or continual approach before God" (NET Bible, footnote to Matt. 7:7).
As the pursuit proceeds, it becomes progressively more active.
The outcomes of our pursuit are out of our direct control.
All we can do is establish the conditions under which it is natural for God to give us his best. Does one receive without asking; find without seeking; have a door opened without knocking? No! God blesses the pursuit (Heb. 11:6). Therefore, we conclude that God blesses our initiative and effort.
Principle #2: God gives us his best because it is his nature to do so (vv. 9-11).
Jesus provides an example from human parenting.
Can we get Bubble Rockets?
Can I go to the store and buy something?
Can I buy a hat?
Can we go to the candy aisle?
Can I have dessert now?
Can I play soccer in the garage?
Can I get a Poptropica shirt?
Can you play this game for me?
Can you come and fix the computer screen for me?
A human father is generous toward his children.
The child seeks to fulfill basic dietary needs. By implication, the child is absolutely dependent on the father for subsistence.
"Fish and bread were basic staples, integral to the diet of most of Jesus' hearers; they do not stand for the fineries of the wealthy" (Keener, IVP 65).
The human father meets the child's needs and does not respond insensitively to them.
The father does not substitute something useless (a stone) or harmful (a snake) for good things (bread and fish).
In a parallel passage, a request for a fish and an egg are compared with the giving of a snake and a scorpion (Luke 11:11-12).
Jesus draws an analogy between the earthly father and the heavenly Father.
He uses an argument from the lesser to the greater ("how much more"), something that was common in contemporary Jewish thought.
"Jesus adapts a standard Jewish argument here called qal vahomer: arguing from the lesser to the greater (if the lesser is true, how much more the greater)" (Keener, IVP 65).
Earthly fathers give their children good gifts despite their inherent sinfulness ("being evil"). God, having no such sinful nature, is even more disposed than we to give good gifts.
"The reason that persistent prayer will be answered arises in the nature of God. A father's responsibility is to provide for his children, and a faithful father will not mock his children when they present a need to him. God's faithfulness as a Father will not permit Him to deny the requests that His children present to Him" (Pentecost 186).
In a parallel passage, Luke substitutes "the Holy Spirit" where Matthew reads "good gifts" (Luke 11:13). This gives us some indication of the nature of God's gifts; while they may not only be spiritual in nature, they are certainly not for selfish indulgence.
"While such basics do not include mere status symbols or other objects of fleshly appetites, they do include whatever is ultimately for God's kingdom—anything necessary for us to fulfill our life and call" (Keener, Matthew, commentary on Matt. 7:7-12).
Good gifts are not everything that is asked for, but things that are necessary, profitable, and/or truly enjoyable. God is the source of these gifts: "Every good gift and every perfect gift is from above, and cometh down from the Father of lights, with whom is no variableness, neither shadow of turning" (Jas. 1:17).
"[T]his empowerment presupposes that we are ready to be as committed to God's purposes as Elijah and like-minded servants of God were. Such a call to believing prayer supposes a heart of piety submitted to God's will; it would not apply to a man praying to obtain another man's wife or to a woman praying for a nicer car as a status symbol of conspicuous consumption. Although Jesus states the promise graphically, he implicitly addresses only men and women of God who will seek the things God would have them to seek for the good of his kingdom and their basic needs (Mt 6:11, 19-34)" (Keener, Matthew, commentary on Matt. 7:7-12).
Note the identification of God as Father.
"The litany of paternal failure [in the Old Testament] serves as a reminder that only one father is good: God the Father" (Ryken, Wilhoit, and Longman 274).
"Jesus calls God 'Father,' especially in the Gospel of John. Because he is the only begotten Son of God [. . .], some aspects of his divine sonship are unique. [. . .] Yet Jesus also shows us what kind of a heavenly Father we have. He teaches us to go to our Father for everything we need" (Ryken, Wilhoit, and Longman 275).
"Jesus models the intimate nature of prayer as conversation. He related to God as a father, using the Aramaic abba (an intimate term for 'father'), yet this intimacy does not diminish his sense of God's holiness. Except for his agonizing cry on the cross [. . .], he always addresses God as Father in prayer and teaches his disciples to do the same [. . .]" (Ryken, Wilhoit, and Longman 275).
We are incapable of taking care of ourselves and must humbly ask God to meet our basic needs.
Asking for the indulgence of our lusts (comp. Ps. 37:4).
Only those who are God's children can expect their requests to meet with his blessings.
"Jesus' promise is for the righteous—people who share kingdom values—asking basic needs and requests concerning the kingdom" (Keener, Matthew, commentary on Matt. 7:7-10).
John 1:11 explains that in order to become God's children, we must receive Jesus—that is, place our faith in him.
God has a beautiful plan for our lives. His willingness to give us his best is evident: "He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things?" (Rom. 8:32). He intends for us to ask, seek, and knock with the intent of discovering and submitting to his plan. Prayer is a powerful tool when it is leveraged against outcomes that are pleasing to God.
"The boldness with which this text [i.e., Matt. 7:7-8] promises answers to prayer is quite rare in ancient literature" (Keener, IVP 64-65).
"Early Jewish teaching did celebrate God's kindness in answering prayer [. . .], but rarely promised such universal answers to prayer to all of God's people as the language here suggests; only a small number of sages were considered pious enough to have such power with God" (Keener, Matthew, commentary on Matt. 7:7-12).
"God must not be thought of as a reluctant stranger who can be cajoled or bullied into bestowing his gifts [. . .], as a malicious tyrant who takes vicious glee in the tricks he plays [. . .], or even as an indulgent grandfather who provides everything requested of him. He is the heavenly Father, the God of the kingdom, who graciously and willingly bestows the good gifts of the kingdom in answer to prayer" (Carson, commentary on Matt. 7:7-11).
Barbieri, Louis A., Jr. "Matthew." The Bible Knowledge Commentary: An Exposition of the Scriptures by Dallas Seminary Faculty: New Testament Edition. Ed. John F. Walvoord and Roy B. Zuck. N.p.: Victor Books, 1983. 13-94.
Carson, D. A. "Matthew." The Expositor's Bible Commentary. Vol. 8. Grand Rapids: Zondervan, 1984.
---. Matthew. The IVP New Testament Commentary Ser. 1. Downers Grove, IL: InterVarsity, 1997. http://www.biblegateway.com/resources/commentaries/index.php?action=getCommentaryText&cid=1& source=1&seq=i.47.7.3.
Pentecost, J. Dwight. The Words and Works of Jesus Christ: A Study of the Life of Christ. Grand Rapids, MI: Zondervan, 1981.
Ryken, Leland, James C. Wilhoit, and Tremper Longman III. Dictionary of Biblical Imagery. Downers Grove, IL: InterVarsity, 1998.