Worthy - Adj.
 
Desirable, comparable, suitable as being chosen especially as a spouse "the parents found the girl suitable for their son"
Having qualities or abilities that merit recognition in some way.
 

Eve was chosen as a "comparable and suitable",  a "worthy" mate for Adam. -
 
Christ's bride will also be chosen as "worthy", comparable and suitable to Him - having qualities and abilities that "merit" His recognition of her.

Salvation is by grace (God's "unmerited" favor) through the gift of faith. BUT the Bride is "worthy" of Christ !