Nothing settles inside a person on a single testimony. Scripture is the first witness, the outer record that tells you what is possible. It stays a claim you have only heard until a second witness rises to confirm it, and that second witness is your own experience. What another says happened, and what happens in you, must agree before a thing is fixed as fact.
The rock this measures against is God, and God here means your own awareness of being, the I AM in you. A promise read but never lived stands unconfirmed, however often it is repeated. The moment you undergo in yourself what the page told you, the two mouths speak the same word, and the matter is established. One account is a rumor. Two that match are settled truth.