The ordinary definitions of "faith" and "believe" imply intellectual agreement with an idea or accepting something as truth, but pistis means more than that. As used in the Bible, it also implies trust in and reliance on God or Christ, surrender of our wills to God or Christ, and conduct consistent with that surrender1. All those elements are present in any mention of "faith" or "believe" in the New Testament, but from the context we can often see that some of the elements are emphasized.
Unfortunately, there are no words in the English language that capture the full meaning of the original pistis and pisteuo, so we are stuck with the often inadequate words "faith" and "believe."
Now there was a woman who had been suffering from hemorrhages for twelve years. She had endured much under many physicians, and had spent all that she had; and she was no better, but rather grew worse. She had heard about Jesus, and came up behind him in the crowd and touched his cloak, for she said, "If I but touch his clothes, I will be made well." Immediately her hemorrhage stopped; and she felt in her body that she was healed of her disease. Immediately aware that power had gone forth from him, Jesus turned about in the crowd and said, "Who touched my clothes?" And his disciples said to him, "You see the crowd pressing in on you; how can you say, 'Who touched me?' " He looked all around to see who had done it. But the woman, knowing what had happened to her, came in fear and trembling, fell down before him, and told him the whole truth. He said to her, "Daughter, your faith has made you well; go in peace, and be healed of your disease." (NRSV, Mark 5:25-34)
The story of the woman with a hemorrhage also has a lesson. If we approach God with humility and put our confidence and trust in Him instead of in worldly things, our faith will enable our spiritual healing and salvation.
John 3:16 is one of the best known and most beloved verses in the Bible, but it must be read in context to appreciate its full meaning and implications:
14 And just as Moses lifted up the serpent in the wilderness, so must the Son of Man be lifted up, 15 that whoever believes in him may have eternal life.
16 "For God so loved the world that he gave his only Son, so that everyone who believes in him may not perish but may have eternal life.
17 "Indeed, God did not send the Son into the world to condemn the world, but in order that the world might be saved through him. 18 Those who believe in him are not condemned; but those who do not believe are condemned already, because they have not believed in the name of the only Son of God.
19 And this is the judgment, that the light has come into the world, and people loved darkness rather than light because their deeds were evil. 20 For all who do evil hate the light and do not come to the light, so that their deeds may not be exposed.
21 But those who do what is true come to the light, so that it may be clearly seen that their deeds have been done in God." (NRSV, John 3:14-21)
From the verses immediately before and after John 3:16, we can see that the word "believe" (translated from pisteuo) brings to mind these ideas:
A group of people known as Judaizers opposed Paul's ministry to the Gentiles. They told the Gentile converts to Christianity that they must observe all of the Jewish Law - circumcision, dietary restrictions, and all the many other rules and laws. But Paul said that was wrong; salvation comes through faith in Jesus Christ, not by observing the Jewish Law.
Galatia, a region of central Asia Minor (modern Turkey), was one of the places the Judaizers were active. Paul wrote this to the Galatian Christians to correct the false teachings of the Judaizers:
We ourselves are Jews by birth and not Gentile sinners; yet we know that a person is justified not by the works of the law but through faith in Jesus Christ. And we have come to believe in Christ Jesus, so that we might be justified by faith in Christ, and not by doing the works of the law, because no one will be justified by the works of the law. (NRSV, Galatians 2:15-16)
Paul's teaching has sometimes been interpreted as meaning that if we have faith, nothing else matters; we don't need to repent of sin or do the "good works" of obeying God's commandments and helping other people. But that was not Paul's interpretation at all. He said if the Spirit of Christ is truly within us, we will turn away from evil deeds:
The acts of the sinful nature are obvious: sexual immorality, impurity and debauchery; idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God. But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control. Against such things there is no law. Those who belong to Christ Jesus have crucified the sinful nature with its passions and desires. Since we live by the Spirit, let us keep in step with the Spirit. Let us not become conceited, provoking and envying each other. (NIV, Galatians 5:19-26)
Martin Luther (1483-1546), was a Catholic monk and Professor of Scripture at the University of Wittenberg in Germany. From his study of Scripture, Luther knew that the "good works" of giving money to the Church did not have the power to forgive people's sins. Instead, Luther taught that we can be justified (made acceptable to God) only by faith.
But Luther did not deny the importance of other good works such as obeying God's commandments, helping other people, etc. He wrote, "For grace and faith are infused apart from our work, and when they are infused, then the works follow." In other words, when one is saved by the grace of God, through faith, he or she will practice good works as a result of that transformation. He also taught that a believer must practice repentance throughout his or her whole life.
In 1517, Luther tacked his famous 95 theses entitled "On the Power of Indulgences" to the door of the castle church at Wittenberg. That document was a scathing indictment of the practice of selling indulgences, and it set off the chain of events that led to the Protestant Reformation. However, the Catholic Church soon undertook its own reforms and the practice of selling indulgences was abolished.
It is a great comfort to know we do not have to be perfect to find God's favor. Even the worst of sinners can become a new creation in Christ (2 Corinthians 5:17) through faith. Then, through good works and repentance, the light of Christ will shine brightly in our lives (Matthew 5:16, Luke 15:7).
Some people see evidence of God in the life and teachings of Jesus. Some see evidence of God’s creation in the intricacies and wonders of the universe and life. Some may perceive God in the gift of life and the miracle of birth. Some see evidence of God in the beauty of the world. Some see God in unselfish love (1 John 4:7-8).
Other people see the sometimes hypocritical and cynical actions of Christians and religious leaders as a reason not to believe. However, the failures of some Christians does not disprove the existence and goodness of God.
Some people see the evils of war, crime, prejudice, greed and poverty and the tragedies of natural disasters and death as reasons to reject God. But others see the gift of life, the gift of unselfish love, the opportunity to serve others and the promise of a glorious eternal life as reasons for faith, hope and optimism.
The person afraid to get in the water will never learn to swim. Similarly, the person afraid to believe without knowing all the answers will never find faith.
For my thoughts are not your thoughts,
nor are your ways my ways, says the Lord.
For as the heavens are higher than the earth,
so are my ways higher than your ways
and my thoughts than your thoughts.
(NRSV, Isaiah 55:8-9)
And the apostle Paul wrote this:
Love never fails. But where there are prophecies, they will cease; where there are tongues, they will be stilled; where there is knowledge, it will pass away. For we know in part and we prophesy in part, but when completeness comes, what is in part disappears. When I was a child, I talked like a child, I thought like a child, I reasoned like a child. When I became a man, I put the ways of childhood behind me. For now we see only a reflection as in a mirror; then we shall see face to face. Now I know in part; then I shall know fully, even as I am fully known. (TNIV, 1 Corinthians 13:8-12)
What Does the Bible Say About Salvation?
What Does the Bible Say About Forgiveness of Sins?
Why Does God Allow Evil Things to Happen?
1W. E. Vine, et. al., Vine's Expository Dictionary of Biblical Words, Second edition, 1985, Thomas Nelson Publishers.