"Faith" is one of the Bible's most used words and one of the most misunderstood. In everyday English it can mean believing something without evidence, or a vague religious feeling, or a denomination. In the Bible the word (pistis in Greek, from a family of words meaning trust and faithfulness) means something more concrete: relying on God, taking him at his word, and acting on it. Faith is less like believing a theory and more like trusting a bridge enough to walk across.

The twenty passages below show that meaning from several angles: what faith is, where it comes from, the people who had it, what it can do, how it fails and recovers, and how it holds under pressure. Quotations are from the Berean Standard Bible; every reference links to the chapter. For more, see the faith topic hub.

What faith is

Hebrews 11:1

Now faith is the assurance of what we hope for and the certainty of what we do not see.

— Hebrews 11:1

The Bible's nearest thing to a definition. The King James Version's "the substance of things hoped for, the evidence of things not seen" is the wording most people know. Faith is not the absence of evidence; it is the confidence that treats God's promises as solid ground before they are visible.

Hebrews 11:6

And without faith it is impossible to please God, because anyone who approaches Him must believe that He exists and that He rewards those who earnestly seek Him.

— Hebrews 11:6

Two beliefs are named: that God is, and that he responds to those who seek him. Faith, in other words, is relational before it is doctrinal.

2 Corinthians 5:7

For we walk by faith, not by sight.

— 2 Corinthians 5:7

Six words, and the whole Christian life. "Walk" is Paul's usual word for how a person lives day to day. Faith is not an occasional leap but a way of walking.

Romans 10:17

Consequently, faith comes by hearing, and hearing by the word of Christ.

— Romans 10:17

Where faith comes from. It is not manufactured by effort; it grows in response to hearing what God has said and done.

The people who had it

Genesis 15:6 and Romans 4

Abram believed the LORD, and it was credited to him as righteousness.

— Genesis 15:6

The Bible's first great sentence about faith, and the one Paul built Romans 4 on. Abraham, childless and old, believed God's promise of descendants, and God counted that trust as righteousness. Paul describes what it looked like: "Against all hope, Abraham in hope believed … without weakening in his faith, he acknowledged the decrepitness of his body … Yet he did not waver through disbelief in the promise of God, but was strengthened in his faith and gave glory to God" (Romans 4:18–20). Faith here is not ignoring the facts; Abraham "acknowledged" them. It is trusting God's promise more than the facts.

Hebrews 11:8–10

By faith Abraham, when called to go to a place he would later receive as his inheritance, obeyed and went, without knowing where he was going.

— Hebrews 11:8

Hebrews 11 is the Bible's hall of faith, a chapter of "by faith" sentences about Abel, Enoch, Noah, Abraham, Sarah, Moses, Rahab, and others. Notice the verb attached to each: obeyed, went, offered, refused, passed through. In Hebrews, faith is always something people did.

Habakkuk 2:4

Look at the proud one; his soul is not upright — but the righteous will live by faith.

— Habakkuk 2:4

A prophet's line, written while waiting for God to act against injustice, that became the New Testament's summary of the gospel. Paul quotes it in Romans 1:17 and Galatians 3:11, and it was the verse that turned Martin Luther's understanding of God.

Faith and salvation

Ephesians 2:8–9

For it is by grace you have been saved through faith, and this not from yourselves; it is the gift of God, not by works, so that no one can boast.

— Ephesians 2:8–9

Faith is the hand that receives, not the work that earns. Grace is the source, faith the means, and even the faith is a gift.

Romans 10:9–10

If you confess with your mouth, "Jesus is Lord," and believe in your heart that God raised Him from the dead, you will be saved. For with your heart you believe and are justified, and with your mouth you confess and are saved.

— Romans 10:9–10

The content of saving faith, stated plainly: Jesus is Lord, and God raised him from the dead. Belief in the heart and confession with the mouth belong together.

Romans 5:1–2

Therefore, since we have been justified through faith, we have peace with God through our Lord Jesus Christ, through whom we have gained access by faith into this grace in which we stand.

— Romans 5:1–2

Galatians 2:20

I have been crucified with Christ, and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave Himself up for me.

— Galatians 2:20

Faith after conversion is not a one-time transaction but the way the whole life is lived: "by faith in the Son of God, who loved me."

Faith and works

James 2:17 and 2:26

So too, faith by itself, if it does not result in action, is dead.

— James 2:17

James is often set against Paul, but they are answering different questions. Paul asks how a person is made right with God, and answers: by faith, not works. James asks what real faith looks like, and answers: it acts. A faith that leaves a brother hungry while wishing him well is, James says, no faith at all. "As the body without the spirit is dead, so faith without deeds is dead" (verse 26). Paul would agree; his letters end in instructions.

Faith the size of a seed

Matthew 17:20 and Luke 17:5–6

If you have faith the size of a mustard seed, you can say to this mountain, "Move from here to there," and it will move.

— Matthew 17:20

The disciples asked Jesus to increase their faith, and he answered that a mustard seed's worth would do (Luke 17:5–6). The point is not the size of the faith but the size of the one it rests on. A small trust in a great God moves more than a great trust in oneself.

Mark 11:22–24

"Have faith in God," Jesus said to them. … Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours.

— Mark 11:22, 24

One of the Bible's strongest statements about believing prayer, and one that the rest of Scripture keeps within bounds: James warns that prayers asked "with wrong motives" go unanswered, and John says God hears what is asked "according to His will." Faith is confidence in God, not a technique for bending him.

When faith is weak

Mark 9:23–24

"If You can?" echoed Jesus. "All things are possible to him who believes!" Immediately the boy's father cried out, "I do believe; help my unbelief!"

— Mark 9:23–24

The most honest prayer in the Gospels, and Jesus answered it. Faith and doubt lived in the same man at the same moment, and the small faith was enough. This verse is for everyone who has been told they do not believe hard enough.

Matthew 14:29–31

Then Peter got down out of the boat, walked on the water, and came toward Jesus. But when he saw the strength of the wind, he was afraid, and beginning to sink, cried out, "Lord, save me!" Immediately Jesus reached out His hand and took hold of Peter.

— Matthew 14:29–31

Peter's faith got him out of the boat and his fear started to sink him. What saved him was neither; it was the hand that reached out. Faith that fails halfway still ends in Jesus's grip.

James 1:6

But he must ask in faith, without doubting, because he who doubts is like a wave of the sea, blown and tossed by the wind.

— James 1:6

James is speaking of the double-minded person who asks God for wisdom while planning to ignore it. Honest doubt that still turns to God, like the father in Mark 9, is a different thing from a divided heart.

Faith under pressure

1 Peter 1:7–9

so that the proven character of your faith—more precious than gold, which perishes even though refined by fire—may result in praise, glory, and honor at the revelation of Jesus Christ. Though you have not seen Him, you love Him; and though you do not see Him now, you believe in Him and rejoice with an inexpressible and glorious joy.

— 1 Peter 1:7–8

Written to persecuted churches. Trials are the fire that shows whether faith is gold.

Hebrews 12:1–2

Let us run with endurance the race set out for us. Let us fix our eyes on Jesus, the author and perfecter of our faith, who for the joy set before Him endured the cross.

— Hebrews 12:1–2

The hall of faith in chapter 11 ends here: the way to keep faith is to look at the one who started it and will finish it.

John 20:29

Jesus said to him, "Because you have seen Me, you have believed; blessed are those who have not seen and yet have believed."

— John 20:29

Spoken to Thomas, and to everyone since.

1 John 5:4

And this is the victory that has overcome the world: our faith.

— 1 John 5:4

How to use these verses

  • Start with what faith is. Hebrews 11:1 and 2 Corinthians 5:7 keep the word from drifting into vagueness.
  • Feed it. Romans 10:17 says faith comes by hearing the word of Christ. Read a Gospel; see our guide to starting.
  • Pray Mark 9:24. "I do believe; help my unbelief" is a complete prayer, and it was answered.
  • Let it act. James 2 is the test. Faith that changes nothing is not what the Bible means.
  • Memorize one. Hebrews 11:1 or Galatians 2:20; the memorization guide takes a week.

FAQ

What is the biblical definition of faith?

Hebrews 11:1: "the assurance of what we hope for and the certainty of what we do not see." In practice, faith in the Bible means trusting God and acting on his word, as Abraham did when he believed God's promise and went where he was sent.

What is the most famous Bible verse about faith?

Hebrews 11:1 is the most quoted definition; Ephesians 2:8–9 ("by grace you have been saved through faith") and 2 Corinthians 5:7 ("we walk by faith, not by sight") are close behind. Mark 9:24, "I do believe; help my unbelief," is the most loved.

Does the Bible say faith without works is dead?

Yes, James 2:17 and 2:26. James is not contradicting Paul's teaching that we are justified by faith; he is insisting that real faith shows itself in action. Faith that never acts is not the trust the Bible describes.

What does "faith the size of a mustard seed" mean?

Jesus's answer to disciples who asked for more faith: even a tiny trust, placed in God, is enough to do great things. The emphasis is on the object of faith, not its quantity.

Where does faith come from?

Romans 10:17 says faith comes from hearing the word of Christ, and Ephesians 2:8 calls it a gift of God. It grows by hearing what God has done and responding to it, not by straining to believe harder.