Archaic KJV Word
Virtue
Modern equivalent: power
What Was Lost
The inseparable link between moral character and actual power. When Jesus said virtue went out of Him, the word conveyed that His moral perfection was itself a force -- holiness was not passive goodness but active, tangible energy that could heal.
Closest Survivor in Modern English
virtuosity (retains the 'power through excellence' sense in performance)
Peak Usage (1611)
KJV Luke 8:46 -- 'I perceive that virtue is gone out of me' (Jesus at the healing of the woman)
Died ~1900
Narrowed from 'power/force/excellence' (Latin virtus, from vir 'man/strength') to 'moral goodness,' severing the connection between moral character and actual power.
What Replaced It
“power”
Morally neutral; virtue-as-power meant that genuine goodness carried inherent force
“healing energy”
New Age overtones; virtue was specifically moral power that produced physical effects
“moral excellence”
Abstract and passive; virtue implied that excellence was an active, outflowing force