In short, there is NO difference between faith and belief. Additional meaning has been added to the English word “faith” over time, but in the Greek, the verb for believe is πιστεύω “pisteuo,” and the noun form is πίστις “pistis.” The Greek word “pistis” could just as legitimately be translated “belief” in any place the word “faith” has been used by the translators in the New Testament. It is the same thing as in English, “believe” and “belief” have the same meaning, they are just the verb and noun forms.
In the KJV [and also the NIV & ESV], there is one verse that translates the Greek word “pistis” as “belief:” “But we are bound to give thanks alway to God for you, brethren beloved of the Lord, because God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief [pistis] of the truth: [2 Thessalonians 2:13]. I would assume it is because “faith of the truth” sounds strange, however, some translations actually do translate it like that.
I recently heard a well-known Pastor on a Youtube video say something like “You can’t be saved by belief, you have to have faith!” What? The entire video was actually a little confusing.
However, if he had looked for the definition of belief in the BlueletterBible in the definition of “pistis” he would have found the same confusing definition “belief with the predominate idea of trust (or confidence) whether in God or in Christ, springing from faith in the same.” [Belief springs from belief?]
The first part of the definition of pistis in the BlueLetterBible is correct, belief in Jesus Christ is putting your trust or confidence in His finished worked on the cross, which reconciled us to God, and His resurrection from the Dead which saves us. [Romans 5:10]
When Paul talks about Abraham’s faith the word “faith” is not found in the Genesis account. And even the Septuagint does not use the word “pistis” in that passage. Genesis 15:6 states that “Abraham believed God and it was counted to him for righteousness.” In Romans 4:9, Paul called Abraham’s belief, “pistis” which is translated “faith” in the New Testament.
“For by grace are ye saved through faith [belief]; and that not of yourselves: it is the gift of God; Not of works, lest any man should boast.” Ephesians 2:8-9.