Archaic KJV Word
Grace
Modern equivalent: unmerited favor
What Was Lost
The power dimension. Greek charis was not merely God's attitude but God's enabling energy. 'My grace is sufficient' meant 'My power working through your weakness is enough.' Grace was divine capacity deposited into human frailty -- an active force, not just a favorable opinion.
Closest Survivor in Modern English
grace (still used in theology but most people think it means 'being nice' or a prayer before dinner)
Peak Usage (1611)
KJV Ephesians 2:8 -- 'By grace are ye saved through faith'; 2 Corinthians 12:9 -- 'My grace is sufficient'
Died still used but thinned (~1900)
Detached from Hebrew chen ('favor shown by a superior to an inferior') and Greek charis ('divine enabling power/gift') into vague pleasantness -- 'graceful movement' and 'saying grace before meals.'
What Replaced It
“unmerited favor”
Correct but clinical; grace was not just attitude but active divine power entering human weakness
“kindness”
Horizontal and mild; grace was vertical -- a king stooping to empower a subject
“gift”
Generic; grace was specifically God's empowering presence that transforms incapacity into capability