Definitions: To believe, have faith in, trust. Particularly, to be firmly persuaded as to something, to believe, with the idea of hope and certain expectation.

1. With an adjunct of the thing believed, followed by the acc. of the thing.
2. In the passive.
3. Followed by eis, unto, with the acc.
4. By HOti, that.
5. By peRI, about, concerning, and the gen.

References:

Rom 14:2; Mark 11:23; Rom. 6:8; 10:9; Acts 18:8.

1. 1 Cor. 13:7; 1 John 4:16.
2. 2 Thess. 1:10.
3. John 11:26; 1 John 5:10.
4. John 14:10; Rom. 10:9.
5. John 9:18.

Mark 11:22-23--"Have faith (PIStin) in God," Jesus answered.  23  "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt (diakriTHE-) in his heart but believes (pisTEUse-) that what he says will happen, it will be done for him. (NIV)

Rom. 14:2--One believes (pisTEUei) he may eat anything, while the weak man eats only vegetables.  3  Let not him who eats despise (exoutheNEIto-) him who abstains, and let not him who abstains pass judgment on (kriNEto-) him who eats; for God has welcomed him. (RSV)
Alt.:--One man's faith allows him to eat everything, but another man, whose faith is weak, eats only vegetables.  3  The man who eats everything must not look down on him who does not, and the man who does not eat everything must not condemn the man who does, for God has accepted him. (NIV)

Faith

Origin: Middle English faith, feith; Old French feid; Latin fides, faith, belief, trust, from fidere, to trust, confide in.

Definitions:

1. The assent of the mind to the truth of what is declared by another, resting on his authority and veracity, without other evidence, or on probable evidence of any kind; assent of the mind to a statement or proposition of another, on the ground of the manifest truth of such statement or proposition; firm and earnest belief, on probable evidence of any kind; as, I have strong faith, or no faith, in the testimony of a witness.
2. The assent of the mind to what is given forth as a revelation of man's relation to God and the infinite; a settled conviction in regard to religion; specifically, in Christian theology,
   1. belief in the historic truthfulness of the Scripture narrative and the supernatural origin of its teaching; also called historical or speculative faith;
   2. the assent of the mind to the truth of divine revelation, on the authority of God's testimony, accompanied by a cordial assent of the will or approbation of the heart; an entire confidence or trust in God's character and declarations, and in the character and doctrines of Christ, with an unreserved surrender of the will to his guidance, and dependence on his merits for salvation; also called evangelical, justifying, or saving faith.
3. The object of belief; a doctrine or system of doctrines believed, whether scientific, political, or religious; especially, a creed; a religious system; specifically, the Christian religion.
4. Faithfulness; fidelity; a strict adherence to duty and fulfilment of promises.
5. Word or honor pledged; promise given; fidelity; as, violated his plighted faith.
6. Credibility or truth [Rare.]

Faith is something superior to knowledge and is its criterion. Conjecture, which is only a feeble supposition, is a counterfeit faith.

Now he is faithful who keeps inviolably what is entrusted to him.

We have discovered faith to be the first movement towards salvation. After faith, fear, hope, and repentance (accompanied by temperance and patience) lead us to love and knowledge.

We say, then, that faith must not be inert and alone. Rather, it should be accompanied with investigation. For I do not say that we are not to inquire at all.

Trusting is more than faith. For when one has believed that the Son of God is our Teacher, he trusts that His teaching is true.

Faith, so to speak, is a comprehensive knowledge of the essentials. And knowledge is the strong and sure demonstration of what is received by faith. It is built upon faith by the Lord's teaching.

In my opinion, the faith they possessed was firm, for it was followed by works of faith.

Origen (c. 248 AD): Who enters on a voyage, contracts a marriage, becomes the father of children, or sows seed into the ground--without believing that better things will result from doing so? ... If the hope and belief of a better future is the support of life in every uncertain enterprise, ... why should not this faith rather be rationally accepted by him who believes on better grounds ... in the existence of a God who was the Creator of all these things?

1. In relation to God it means that love takes God at His word, that it believes absolutely in His promises, that it can take every promise which begins "Whosoever" and say, "That means me." It is the love which springs from the faith which "bets its life that there is a God."
2. In relation to our fellow men it means the love which always believes the best about other people. It is always true that we make people what we believe them to be. If we act in such a way that we show that we do not trust people, that we regard them with suspicion, we make them untrustworthy. If we act in such a way that we show people that we trust them absolutely, unless they are lost to honour, we make them trustworthy.

The boys found it difficult to believe. When they were brought before him they continued to make the old excuses and to tell the old lies.

"Boys," he said, "if you say so, it must be true--I believe your word."

The result was that there came a time in Rugby when boys said, "It is a shame to tell Arnold a lie--he always believes you."

He believed in them and he made them what he believed them to be. Love ennobles even the ignoble by believing the best.

BT Internet:  pisteuw, have faith, have confidence in.

St. John Chrysostom, Homily 33:  "Believeth all things." "For it doth not merely hope," saith he, "but also believeth from its great affection."

Adam Clarke:  Believeth all things -- panta pisteuei -- Is ever ready to believe the best of every person, and will credit no evil of any but on the most positive evidence; gladly receives whatever may tend to the advantage of any person whose character may have suffered from obloquy and detraction; or even justly, because of his misconduct.

John Gill's Exposition of the Bible:  believeth all things; that are to be believed, all that God says in his word, all his truths, and all his promises; and even sometimes in hope against hope, as Abraham did, relying upon the power, faithfulness, and other perfections of God; though such a man will not believe every spirit, every preacher and teacher, nor any but such as agree with the Scriptures of truth, the standard of faith and practice; nor will he believe every word of man, which is the character of a weak and foolish man; indeed, a man of charity or love is willing to believe all the good things reported of men; he is very credulous of such things, and is unwilling to believe ill reports of persons, or any ill of men; unless it is open and glaring, and is well supported, and there is full evidence of it; he is very incredulous in this respect.

John W. Gregson:  Love does not look with suspicion upon others.

Matthew Henry:  Wisdom may dwell with love, and charity be cautious. But it is apt to believe well of all, to entertain a good opinion of them when there is no appearance to the contrary; nay, to believe well when there may be some dark appearances, if the evidence of ill be not clear. All charity is full of candour, apt to make the best of every thing, and put on it the best face and appearance; it will judge well, and believe well, as far as it can with any reason, and will rather stretch its faith beyond appearances for the support of a kind opinion; but it will go into a bad one with the utmost reluctance, and fence against it as much as it fairly and honestly can.

Jamieson, Fausset, & Brown:  believeth all things -- unsuspiciously believes all that is not palpably false, all that it can with a good conscience believe to the credit of another. Compare Jas 3:17, "easy to be entreated"; Greek, "easily persuaded."

BW Johnson:  Believeth all things. Is not distrustful and suspicious.

Mark Heber Miller:  (Love) believes all things.

This phrase may have more than one meaning. The phrase is variously rendered: WMS: it exercises faith in everything; BER: unquenchable faith; MOF: always eager to believe the best; NEB: there is no limit to its faith; PME: no limit to its trust. If the Greek PISTEUEI is viewed more as "trust" then this kind of love always trusts a friend’s truthfulness or honesty. This love is not paranoid, distrusting, or suspicious. There is a certain guilelessness in such a loving person. This person has no agenda, is no manipulator. These loving persons take people as they are without judging them wrongly without strong evidence to the contrary.

Translator James Moffatt may have come the closest: "(love) is always eager to believe the best." What a Christ-like attitude to trust and believe that there is some goodness in everyone.

Robertson's Word Studies:  {Believeth all things} (panta pisteuei). Not gullible, but has faith in men.

Bill Turner:  Love believeth all things, it has no limit to its faith and trust, "Panta pisteuei."

Love is not gullible, but it does not give people up as hopeless when the evidence is heavily against them. Prov.14v15. 1Thes.5v12. Even when there are dark signs in a person's life, love gives themselves to believing prayer on their behalf, and trusts God to bring them through. Love also has a perfect trust in the Word, love and provision of God. Phil.1v6. Faith based on love is a present tense reality, and it is an infectious faith that encourages others to trust in God. Heb.3v13.