"Faith"

Faith is the simplest of all things, and perhaps because of its simplicity it is the more difficult to explain. What is faith? It is made up of three things—knowledge, belief, and trust.
KNOWLEDGE…
Knowledge comes first. “How shall they believe in him of whom they have not heard?” (Romans 10:14). I want to be informed of a fact before I can possibly believe it. “Faith comes by hearing” (Romans 10:17); we must first hear, in order that we may know what is to be believed. “Those who know your name will trust in you” (Psalm 9:10)
A measure of knowledge is essential to faith; hence the importance of getting knowledge. “Incline your ear, and come unto me; hear, and your soul shall live” (Isaiah 55:3). Such was the word of the ancient prophet, and it is the word of the gospel still.
Search the Scriptures and learn what the Holy Spirit teaches concerning Christ and His salvation. Seek to know God: “For he that comes to God must believe that he is, and that he is a rewarder of them that diligently seek him” (Hebrews 11:6). May the Holy Spirit give you the spirit of knowledge, and of the fear of the Lord! Know the gospel: know what the good news is, how it talks of free forgiveness, and of change of heart, of adoption into the family of God, and of countless other blessings.
Know especially Christ Jesus the Son of God, the Savior of men, united to us by His human nature, and yet one with God; and thus able to act as Mediator between God and man, able to lay His hand upon both, and to be the connecting link between the sinner and the Judge of all the earth.
Endeavor to know more and more of Christ Jesus. Endeavor especially to know the doctrine of the sacrifice of Christ; for the point upon which saving faith mainly fixes itself is this— “God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them” (2 Corinthians 5:19). Know that Jesus was “made a curse for us, as it is written, Cursed is every one that hangs on a tree” (Galatians 3:13). Drink deep of the doctrine of the substitutionary work of Christ; for there lies the sweetest possible comfort to the guilty sons of men, since the Lord “made him to be sin for us, that we might be made the righteousness of God in him.” (2 Corinthians 5:21). Faith begins with knowledge.
BELIEF…
The mind goes on to believe that these things are true. The soul believes that God is, and that He hears the cries of sincere hearts; that the gospel is from God; that justification by faith is the grand truth which God has revealed in these last days by His Spirit more clearly than before.
Then the heart believes that Jesus is verily and in truth our God and Savior, the Redeemer of men, the Prophet, Priest, and King of His people. All this is accepted as sure truth, not to be called in question. I pray that you may at once come to this. Get firmly to believe that “the blood of Jesus Christ, God’s dear Son, cleanse us from all sin” (1 John 1:7); that His sacrifice is complete and fully accepted of God on man’s behalf, so that he that believe on Jesus is not condemned. Believe these truths as you believe any other statements; for the difference between common faith and saving faith lies mainly in the subjects upon which it is exercised. Believe the witness of God just as you believe the testimony of your own father or friend. “If we receive the witness of men, the witness of God is greater” (1 John 5:9).
TRUST…
So far you have made an advance toward faith; only one more ingredient is needed to complete it, which is trust. Commit yourself to the merciful God; rest your hope on the gracious gospel; trust your soul on the dying and living Savior; wash away your sins in the atoning blood; accept His perfect righteousness, and all is well.
Trust is the lifeblood of faith; there is no saving faith without it. The Puritans were accustomed to explain faith by the word “recumbency.” It meant leaning upon a thing. Lean with all your weight upon Christ. It would be a better illustration still if I said, fall at full length, and lie on the Rock of Ages. Cast yourself upon Jesus; rest in Him; commit yourself to Him.
That done, you have exercised saving faith. Faith is not a blind thing; for faith begins with knowledge. It is not a speculative thing; for faith believes facts of which it is sure. It is not an unpractical, dreamy thing; for faith trusts, and stakes its destiny upon the truth of revelation. That is one way of describing what faith is.
Let me try again. Faith is believing that Christ is what He is said to be, and that He will do what He has promised to do, and then to expect this of Him.
- Charles Spurgeon