For those who are interested in the process...
Few basic assumptions to start off with - cryptography likes the ol' Occam's Razer ("The simplest solution is the most likely") so we assume that
each letter in the cypher corresponds to ONE specific letter in the alphabet until we can prove otherwise, at which point we can get into more complicated possibilities. We will also assume that the spaces between letters in the cypher represent normal word breaks.
Tbh the easiest part of this one was the provision of "M. A. BVXQA" at the end. The single letters can't be the words 'I' or 'a' in this context, so it must be some form of initialisation. The most likely possibility is that it's
First initial Second Initial Surname. So I started thinking of potential quotable figures that fit that pattern. J.K. Rowling and J.D. Salinger are out because the surname needs to be five letters, and it couldn't be E.B. White because that would require the first initial to be the same letter as the final letter of the surname. Disappointingly, that also rules out E.L. James (a.k.a. literary mastermind behind the
50 Shades series). That left me with a few possibilities: T.S. Eliot, W.B. Yeats, W.H. Auden, etc. But the second initial had to match the last letter of the surname, and the only name I could think of that meets that requirement was C.S. Lewis. So then I started substituting those letters in:
ARNV JWS SRL XQBB OV RBJ VURLCG KR AKWYK YVWJQUC PWQYS KWBVA WCWQU. M. A. BVXQA
s??e ?? ? ?? ? will ?e ?l? e?? ?? ? ?? s?? ?? ?e??i?? ??i?? ??les ?? ?i?. C. S. Lewis
Side note: 'V' is one of the most frequently occurring letters in the cypher too, so this semi-confirms you're on the right track, though frequency-testing other letters isn't wholly useful with such a small set of data.)
From there, I could've just googled 'C.S. Lewis quotes' and checked to see if any matched up, especially now that I know the word "will" has to be there. But I wanted to see how far I could get on my own. The word 'OV' had limited possibilities since there aren't too many two letter words ending in 'e.' It can't be 'we' since 'w'='X,' and it's unlikely to be 'me' since the word appears after 'will,' so I assumed that one was 'be' and therefore that 'b'='O.' There was also another two letter word - 'KR' that I didn't have any letters for. But it had to contain a vowel, and (back to high-frequency words, which is sort of simultaneously cheating and unreliable but w/evs) the word 'to' was highly likely. This got me to:
ARNV JWS SRL XQBB OV RBJ VURLCG KR AKWYK YVWJQUC PWQYS KWBVA WCWQU. M. A. BVXQA
so?e ?? ? ?o? will be ol? e?o?? ? to st??t ?e??i?? ??i?? t?les ?? ?i?. C. S. Lewis
From there, left to right, I assumed that:
'm'='N,' so the first word is 'some'
'y'='S', and 'o'='L', so the second word is 'you'
'd'='J', so the sixth word is 'old'
'a'='W' and 'r'='Y', so the ninth word is 'start'
This resulted in:
ARNV JWS SRL XQBB OV RBJ VURLCG KR AKWYK YVWJQUC PWQYS KWBVA WCWQU. M. A. BVXQA
some ?ay you will be old e?ou?? to start readi?? ?airy tales a?ai?. C. S. Lewis
From there it's pretty easy to fill in the gaps, giving us 'day,' 'enough,' 'reading,' fairy,' and 'again.' I also recognised the quote at that point, which made it even easier :P
So yeah, now I've explained the magic to you, that probably sounds way less impressive...