Hebrew 11

Paul taught the Jews -

"NOW faith is the substance of things hoped for, the evidence of things not seen."  (New Testament | Hebrews 11:1)

Joseph Smith translated "substance" as "assurance".  Substance would suggest confidence and foundation, while assurance, in my mind, would add some sort of feelings or influence either for the Holy Ghost or ministering angels.  Either way, I think the definition is correct.  As I have written previously, I see faith as a principle of action and power for -

"...without faith it is impossible to please him..."  (New Testament | Hebrews 11:6)

As Paul continues to provide examples of faith, he suggests an interesting experience writing -

"By faith Abel offered unto God a more excellent sacrifice than Cain, by which he obtained witness that he was righteous, God testifying of his gifts: and by it he being dead yet speaketh."  (New Testament | Hebrews 11:4)

Their is little in Genesis where Paul would know these things but adds "by it he being dead yeat speaketh".  Of that, Joseph Smith explained -

"“How doth he yet speak? Why he magnified the Priesthood which was conferred upon him, and died a righteous man, and therefore has become an angel of God by receiving his body from the dead, holding still the keys of his dispensation; and was sent down from heaven unto Paul to minister consoling words, and to commit unto him a knowledge of the mysteries of godliness. And if this was not the case, I would ask, how did Paul know so much about Abel, and why should he talk about his speaking after he was dead? Hence, that he spoke after he was dead must be by being sent down out of heaven to administer.” (Teachings of the Prophet Joseph Smith, selected and arranged by Joseph Fielding Smith [Salt Lake City: Deseret Book, 1976], p. 168.)

This would suggest that Paul's assurance of hope may have increased with a visit from the ministering angel - Abel.

I would also that with faith we need patience as Paul teaches -

"For ye have need of patience, that, after ye have done the will of God, ye might receive the promise."  (New Testament | Hebrews 10:36)