Countless stories could be cited of diseases cured, exams passed, repentance and forgiveness granted, relationships restored, hungry children fed, bills paid and lives and souls saved through the efficacy of prayer. So, yes, there is plenty of evidence that God answers prayer. Most of the evidence is anecdotal and personal, however, and that bothers many who think of “evidence” only as that which is observable, measureable, and reproducible.
Scripture clearly teaches that prayers are answered. James 5:16 states that “the prayer of a righteous person is powerful and effective.” Jesus taught His disciples that “if you remain in me and my words remain in you, ask whatever you wish, and it will be done for you” (John 15:7). First John 3:22 echoes this truth, saying that we “receive from him anything we ask, because we keep his commands and do what pleases him.”
Scripture, moreover, is replete with stories of answered prayer. Elijah’s prayer for fire from heaven (2 Kings 1:12), Hezekiah’s prayer for deliverance (2 Kings 19:19), and the apostles’ prayer for boldness (Acts 4:29) are just three examples. Since these accounts were written by eyewitnesses to the events, they constitute clear evidence of answered prayer. One might, of course, counter that Scripture does not present observable evidence in the “scientific” sense. However, no statement of Scripture has ever been conclusively disproved, so there is no reason to doubt its testimony. In fact, labeling some kinds of evidence as “scientific” and other kinds as “non-scientific” is a fuzzy and artificial distinction at best. Such a distinction can only be made a priori, i.e., prior to the evaluation of the data. In other words, the choice to evaluate the efficacy of prayer only in light of observable evidence is not a choice motivated by the data but by prior philosophical commitments. When this arbitrary restriction is relaxed, the biblical data speaks clearly for itself.
Occasionally, a group of researchers will conduct a scientific study on the efficacy of prayer. Their findings are usually that prayer has no effect (or possibly even a negative effect) on, for instance, the average recovery time of people in medical care. How are we to understand the results of studies such as these? Are there any biblical reasons for unanswered prayer?
Psalm 66:18 says, “If I regard wickedness in my heart, the Lord will not hear” (NASB). Likewise, 1 John 5:15 qualifies our receiving “anything we ask” with our obedience to God’s commands. James notes that “when you ask, you do not receive, because you ask with wrong motives” (4:3). So, a couple reasons for unanswered prayer are unconfessed sin and wrong motivations.
Another reason for unanswered prayer is lack of faith: “When you ask, you must believe and not doubt, because the one who doubts is like a wave of the sea, blown and tossed by the wind. That person should not expect to receive anything from the Lord” (James 1:6-7). Hebrews 11:6 also identifies faith as a necessary condition for a relationship with God, something always mediated by prayer in the name of Christ: “And without faith it is impossible to please God, because anyone who comes to him must believe that he exists and that he rewards those who earnestly seek him.” Faith, then, is necessary for answered prayer.
Finally, some critics of Christianity make the case that, since Jesus instructs His disciples to “ask whatever you wish,” all prayers should be answered. However, such criticisms completely ignore the conditions to the promise in the first part of the verse: “If you remain in me and my words remain in you.” This is clearly a prescription for praying within the will of God; in other words, genuine prayer which God always answers is, in fact, that sort which requests, explicitly or implicitly, that God’s will be accomplished. The will of the petitioner is secondary. Jesus Himself prayed this way in Gethsemane (Luke 22:42). The humble prayer of faith allows that the prayer may be answered with a “no”; anyone not offering such a prayer—anyone who demands to be answered—has no right to expect an answer.
Another reason why so many studies report the inefficacy of prayer is that it is impossible to eliminate the variables associated with the spiritual condition of those praying (is the petitioner even a believer?), the motivation for which they offer the prayer (is it to provide evidence or because the Holy Spirit has moved them to pray?), the way in which they offer their prayer (are they praying a formulaic expression or intentionally bringing requests to God?), and so on.
Even if all such lurking variables could be eliminated, one overarching problem would remain: if prayer could be tested empirically and forced to yield conclusive results, it would obviate the need for faith. We cannot “discover” God through empirical observations; we come to Him by faith. God is not so clumsy that He should reveal Himself in ways He did not intend. “He who comes to God must believe that He is” (that is, that He exists). Faith is the prerequisite and the priority.
Does God answer prayer? Ask any believer, and you will know the answer. Every changed life of every believer is proof positive that God answers prayer.