Error in KJV

The most indisputable traslation error in the KJV is found Hebrew 10:23, Let us hold fast the profession of our faith without wavering; (for he is faithful that promised;) 

Heb 10:23 κατεχωμεν την ομολογιαν της ελπιδος ακλινη πιστος γαρ ο επαγγειλαμενος 

Everyone concede that the actual Greek word is hope (ελπις)

From Thayer'S Greek Definitions

G1680

ἐλπίς
elpis

Thayer Definition:

1) expectation of evil, fear

2) expectation of good, hope

2a) in the Christian sense

2a1) joyful and confident expectation of eternal salvation

3) on hope, in hope, having hope

3a) the author of hope, or he who is its foundation

3b) the thing hoped for

Part of Speech: noun feminine

A Related Word by Thayer’s/Strong’s Number: from a primary elpo (to anticipate, usually with pleasure)

Citing in TDNT: 2:517, 229

So the better reading is ESV, Heb 10:23 Let us hold fast the confession of our hope without wavering, for he who promised is faithful.