J, 133 135 79 83 84 88 characters (utf-8 encoding)
;/5 3$"1(' ',.s){~"1#:3 u:(ucp'翇篭篯礧歮禧禤祯寭璗牯宭䤧彭忭筯篤筿殭秏璒孯孪寿咕寏犧'){~0>.64-~a.i.s=:
Usage:
;/5 3$"1(' ',.s){~"1#:3 u:(ucp'翇篭篯礧歮禧禤祯寭璗牯宭䤧彭忭筯篤筿殭秏璒孯孪寿咕寏犧'){~0>.64-~a.i.s=:'ABCDEFGHIJKLMNOPQRSTUVWXYZ !'
┌───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┐
│AAA│BBB│CCC│DD │EEE│FFF│GGG│H H│III│JJJ│K K│L │M M│N N│OOO│PPP│QQQ│RR │SSS│TTT│U U│V V│W W│X X│Y Y│ZZZ│ │!!!│
│A A│B B│C │D D│E │F │G │H H│ I │ J│K K│L │MMM│NNN│O O│P P│Q Q│R R│S │ T │U U│V V│W W│ X │Y Y│ Z│ │!!!│
│AAA│BBB│C │D D│EE │FF │G G│HHH│ I │ J│KK │L │M M│NNN│O O│PPP│Q Q│RR │SSS│ T │U U│V V│WWW│ X │YYY│ Z │ │!!!│
│A A│B B│C │D D│E │F │G G│H H│ I │J J│K K│L │M M│N N│O O│P │QQQ│R R│ S│ T │U U│V V│WWW│ X │ Y│Z │ │ │
│A A│BBB│CCC│DD │EEE│F │GGG│H H│III│JJJ│K K│LLL│M M│N N│OOO│P │QQQ│R R│SSS│ T │UUU│ V │WWW│X X│YYY│ZZZ│ │!!!│
└───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┘
;/5 3$"1(' ',.s){~"1#:3 u:(ucp'翇篭篯礧歮禧禤祯寭璗牯宭䤧彭忭筯篤筿殭秏璒孯孪寿咕寏犧'){~0>.64-~a.i.s=:'this is incorrect input.'
|index error
Explanation (NB. is comment in J):
;/ NB. String together along the third dimension...
5 3$"1 NB. ... reshape each line to 5x3...
(' ',.s) NB. ... a space before each letter of the input string...
{~"1 NB. ... indexed using...
#: NB. ... the (15 bit) binary representation of ...
3 u: NB. ... the integer representation of...
(ucp'翇篭篯礧歮禧禤祯寭璗牯宭䤧彭忭筯篤筿殭秏璒孯孪寿咕寏犧') ... the unicode versions of these code points...
{~ NB. ...indexed using...
0>. NB. ...the max of 0 and...
64-~ NB. ...64 less than...
a.i. NB. the ascii indexes of s
s=: NB. Assign the input string to the variable s.