Smile: Seuss

Dr. Seuss said, "Don't cry because it's over. Smile because it happened."

Better angels: Lincoln

Abraham Lincoln, from his: First Inaugural Address:

“I”m loath to close. We are not enemies, but friends. We must not be enemies. Though passion may have strained it must not break our bonds of affection. The mystic chords of memory, stretching from every battlefield and patriot grave to every living heart and hearthstone all over this broad land, will yet swell the chorus of the Union, when again touched, as surely they will be, by the better angels of our nature.” (Emphasis added).

Small Things=Great Things: BOM

"Wherefore, be not weary in well-doing, for ye are laying the foundation of a great work. And out of small things proceedeth that which is great."
D&C 64: 33:

Gradualness: Anon

Never underestimate the inevitability of gradualness.
Anonymous

Move a mountain?: Unk

"If you can't move the mountain, move a few stones." Unknown

Heros: Rogers

"We can't all be heroes because someone has to sit on the curb and clap as they go by." -Will Rogers

Never left alone: Holland

"God never leaves us alone, never leaves us unaided in the challenges that we face."

--Jeffrey R. Holland, "The Ministry of Angels", Ensign, Nov 2008, 29–31