PostgreSQL's trigram-comparing doesn't fare too badly, I think. The trigram functionality is inside module pg_trgm (a contrib module).
I compared your example sentences and asked pg_trgm what similarity it thought they had. pg_trgm expresses that similarity as a number between 0 and 1 (='very different' to 'virtually the same'):
prior | strict_word_similarity | initi
+al part
----------------------------+------------------------+----------------
+--------------------------
(Identical) | 1 | And it came to
+pass, when king Hezekia...
(Only punctuation differs) | 1 | Thou shalt not
+take the name of the LO...
(Similar) | 0.8333333 | The fool hath s
+aid in his heart, There...
(Should rank as similar) | 0.8 | Thou shalt not
+steal.
(Less similar) | 0.45614034 | In the beginnin
+g God created the heave...
(5 rows)
-- (column 3 truncated)
The SQL I used (the db must have pg_trgm installed, which you can do with CREATE EXTENSION pg_trgm;):
select
prior
-- , similarity(txt1, txt2)
, strict_word_similarity(txt1, txt2)
, substring(txt1, 1, 40) -- || chr(10) || txt2
from (values
( '2 Kings 19:1' , 'And it came to pass, when king Hezekiah hea
+rd it, that he rent his clothes, and covered himself with sackcloth,
+and went into the house of the LORD.',
'Isaiah 37:1' , 'And it came to pass, when king Hezekiah hea
+rd it, that he rent his clothes, and covered himself with sackcloth,
+and went into the house of the LORD.' ,
'(Identical)')
, ( 'Exodus 20:7', 'Thou shalt not take the name of the LORD thy God
+ in vain; for the LORD will not hold him guiltless that taketh his na
+me in vain.',
'Deuteronomy 5:11', 'Thou shalt not take the name of the LORD th
+y God in vain: for the LORD will not hold him guiltless that taketh h
+is name in vain.',
'(Only punctuation differs)' )
,
( 'Psalm 14:1' , 'The fool hath said in his heart, There is n
+o God. They are corrupt, they have done abominable works, there is no
+ne that doeth good.',
'Psalm 53:1' , 'The fool hath said in his heart, There is n
+o God. Corrupt are they, and have done abominable iniquity: there is
+none that doeth good.',
'(Similar)' )
,
( 'Exodus 20:15' , 'Thou shalt not steal.',
'Deuteronomy 5:19', 'Neither shalt thou steal.',
'(Should rank as similar)' )
,
( 'Genesis 1:1' , 'In the beginning God created the heaven and
+ the earth.',
'John 1:1' , 'In the beginning was the Word, and the Word
+ was with God, and the Word was God.',
'(Less similar)' )
)
as f(verse1, txt1, verse2, txt2, prior)