Use dwdiff to create word diffs between verses.
The syntax that I like displays the revised version with the additions bolded.
dwdiff -1 -c 1chr.21.15.{kjv,jst}
returns:
15 And God sent an angel unto Jerusalem to destroy {+it. And the angel stretched forth his hand unto Jerusalem to destroy it;+} and {+God said to the angel, Stay now thine hand, it is enough; for+} as he was destroying, the Lord {+beheld Israel, that+} he repented him of the {+evil; therefore the Lord stayed+} the angel that destroyed, {+as he+} stood by the {+threshing floor+} of {+Ornan,+} the Jebusite.
To make it work for the wiki, where it's bolded, change the starting and stopping characters that indicate beginning diffs:
dwdiff -y "**" -z "**" -1 matt5.kjv matt5.jst
An example, 1 Chronicles 21:15:
15 And God sent an angel unto Jerusalem to destroy it. And the angel stretched forth his hand unto Jerusalem to destroy it; and God said to the angel, Stay now thine hand, it is enough; for as he was destroying, the Lord beheld Israel, that he repented him of the evil; therefore the Lord stayed the angel that destroyed, as he stood by the threshing floor of Ornan, the Jebusite.
Matthew 5:19
Whosoever, therefore, shall break one of these least commandments, and shall teach men so to do, he shall in no wise be saved in the kingdom of heaven; but whosoever shall do and teach these commandments of the law until it be fulfilled, the same shall be called great, and shall be saved in the kingdom of heaven.
Isaiah 29:
1 Woe to Ariel, to Ariel, the city where David dwelt! add ye year to year; let them kill sacrifices.
2 Yet I will distress Ariel, and there shall be heaviness and sorrow; for thus hath the Lord said unto me, It shall be unto Ariel;
3 That I the Lord will camp against her round about, and will lay siege against her with a mount, and I will raise forts against her.
4 And she shall be brought down, and shall speak out of the ground, and her speech shall be low out of the dust; and her voice shall be as of one that hath a familiar spirit, out of the ground, and her speech shall whisper out of the dust.
5 Moreover the multitude of her strangers shall be like small dust, and the multitude of the terrible ones shall be as chaff that passeth away; yea, it shall be at an instant suddenly.
6 For they shall be visited of the Lord of hosts with thunder, and with earthquake, and great noise, with storm and tempest, and the flame of devouring fire.
7 And the multitude of all the nations that fight against Ariel, even all that fight against her and her munition, and that distress her, shall be as a dream of a night vision.
8 Yea, it shall be unto them even as unto a hungry man who dreameth, and behold, he eateth, but he awaketh and his soul is empty; or like unto a thirsty man who dreameth, and behold, he drinketh, but he awaketh, and behold, he is faint, and his soul hath appetite. Yea, even so shall the multitude of all the nations be that fight against mount Zion.