unregenerate

adjectives

tenaciously unwilling or marked by tenacious unwillingness to yield
obstinate, stubborn, unregenerate
not reformed morally or spiritually
"unregenerate human nature"; "unregenerate conservatism"
unregenerate, unregenerated
antonym
regenerate
unrepentant and incapable of being reformed
"an unregenerate criminal"
unreformable, unregenerate