Nearly every Christian believer throughout the ages has stories to tell of God answering prayer. These personal, anecdotal stories carry much weight with many, but others desire a more scientific proof—they want measurable, observable, and reproducible evidence for answered prayer.
Is there evidence for answered prayer? Does God answer prayer?
Trying to "test" prayer scientifically is not really possible. Some have tried, usually regarding medical situations. But how would one control for variables? Can you be certain that people are not praying for those in the non-prayer group? Are the ones who are praying actually believers in Jesus and praying to the biblical God? Even if those factors could be controlled, is God not healing a person evidence that He doesn't answer prayer? Sometimes His will is not to heal.
Prayer is a very relational endeavor. God is not some sort of cosmic fairy godmother who grants wishes, or a sort of extra-terrestrial slot machine in which we hope for answered prayer. Prayer is not a method of healing or getting what we want that we can test similar to the way we might test a new drug. Rather, prayer is a means of communication with God.
That being said, there is ample evidence that God really does exist and that He really does answer prayer. The Bible has been as "scientifically proven" as it can be, in that as a document it has held up to historical and archaeological scrutiny. There is no reason to doubt the eye witness accounts it gives. There are plenty of passages in the Bible that clearly state that God answers prayer (James 5:16–18; John 15:7; 1 John 3:22) and countless stories about God answering prayer—sometimes in dramatic fashion.
In 1 Samuel 1 we see Hannah pray for a child; God granted her request and gave her Samuel. In one of the most stunning accounts in the Bible, Elijah calls upon God to consume, with fire, a water soaked and flooded sacrifice he has built before the priests of a false god. God answers Elijah (1 Kings 18).
Answers to Jesus' prayers are given as well, such as the time He prayed for His friend Lazarus to come back from the dead (John 11:1–44), when He prayed before feeding the 4,000 and the 5,000 (Matthew 14:13–21; 15:29–39), and others.
In Acts 12 Peter was imprisoned and miraculously released; we are told that the other believers were gathered together praying (Acts 12:6–19). It was as Paul and Silas were "praying and singing hymns to God" that an earthquake came and opened the prison doors where they had been jailed. The prisoners remained, the jailer and his family came to salvation in Jesus, and Paul and Silas were released from prison the next day (Acts. 16:16–40).
Of course, there are many other accounts in the Bible of answered prayer.
Today we have the accounts of millions of Christians who will testify to God's goodness in answering prayer. It could be argued that some of these are false accounts or even "coincidence." But the sheer volume of anecdotal evidence for answered prayer, from Bible-believing Christians who faithfully walk with God, is not easily dismissed.
It should be noted that God does not always answer our prayers the way we would like. His own Word puts qualifications to God's willingness to answer prayer at times. Psalm 66:18 says God won't hear prayers from those who are wicked. First John 5:14–15 says that the prayers we ask according to God's will are granted. James 4:3 says we sometimes don't receive what we pray for because of wrong motives. James 1:6–8 and Hebrews 11:6 indicate that a lack of faith may hinder our prayers.
Jesus' promise that "Whatever you ask in my name, this I will do, that the Father may be glorified in the Son. If you ask me anything in my name, I will do it" (John 14:13–14) is not a blanket promise to give us anything we want. Rather, it is an invitation to be in tune with His will and to boldly ask God for things based on His work that are in line with His character. God is willing and eager to answer our prayers and to do so in the way that He knows is best (Luke 11:1–13).
Accepting that God sometimes refuses our requests is not a cop-out nor demonstrative of prayer being ineffective. Rather, it is a humble recognition that God knows what is best and is faithful to respond to us in love and truth. Much like an earthly father does not give his child everything he asks for, but does delight to give his child good gifts, our heavenly Father delights to meet with us in prayer and is faithful to respond. As Jesus did in the garden of Gethsemane, we should pray "Nevertheless, not my will, but yours, be done" (Luke 22:42).
God "is able to do far more abundantly than all that we ask or think, according to the power at work within us" (Ephesians 3:20). He invites us to approach Him in prayer—with gratitude, worship, confession, and requests (Matthew 6:9–13; Hebrews 4:14–16; 10:19–23; 1 John 1:9; Matthew 7:7–11). James tells us "… You do not have, because you do not ask. You ask and do not receive, because you ask wrongly, to spend it on your passions" (James 4:2–3). Yes, God answers prayer if we are willing to ask with pure hearts, and He does so according to His will.
Prayer is not something that can be scientifically "proven." If answered prayer could be reduced to a formula, there would be no need to seek out God in faith—people would simply follow the formula. But prayer is not about formula; it is about relationship. Relationship requires trust—relationship with God requires the type of trust we term "faith" (Hebrews 11:1, 6).
Rather than seek evidence for answered prayer in scientific studies, try testing it for yourself. If you are a believer in Jesus Christ, the way has been opened for you. Take God up on His promises and begin to pray (Hebrews 4:14–16; Ephesians 6:18; 1 Thessalonians 5:16–18).
Why pray? What is the purpose of prayer?
How do I know if I'm praying in line with the will of God?
What makes for effective prayer?
What types of prayer are mentioned in the Bible?
What is the importance of daily prayer in the life of a Christian?
Truth about Prayer