Christianity invented no such thing! God did and Christ confirmed it:
Mt. 15:19 For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies:
Mt. 5:28 But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.
2Pe 2:14 Having eyes full of adultery, and that cannot cease from sin; beguiling unstable souls: an heart they have exercised with covetous practices; cursed children:
Ge 6:5 And GOD saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually.
Ge 8:21 And the LORD smelled a sweet savour; and the LORD said in his heart, I will not again curse the ground any more for man’s sake; for the imagination of man’s heart is evil from his youth; neither will I again smite any more every thing living, as I have done.
Pr 24:9 The thought of foolishness is sin: and the scorner is an abomination to men.
Jer 17:9 The heart is deceitful above all things, and desperately wicked: who can know it?