Colossians 3:9-10 KJV
(9) Lie not one to another, seeing that ye have put off the old man with his deeds;
(10) And have put on the new man, which is renewed in knowledge after the image of him that created him:
Ephesians 4:21-24 KJV
(21) If so be that ye have heard him, and have been taught by him, as the truth is in Jesus:
(22) That ye put off concerning the former conversation the old man, which is corrupt according to the deceitful lusts;
(23) And be renewed in the spirit of your mind;
(24) And that ye put on the new man, which after God is created in righteousness and true holiness.
Also, compare with other translations of Ephesians 4:24.
(NET) and to put on the new man who has been created in God’s image 29 – in righteousness and holiness that comes from truth. 30
(ESV) and to put on the new self, created after the likeness of God in true righteousness and holiness.
(YLT) and to put on the new man, which, according to God, was created in righteousness and kindness of the truth.
New English Translation (NET Bible) notes for Ephesians 4:24:
29 Or “in God’s likeness.” Grk “according to God.” The preposition κατά used here denotes a measure of similarity or equality
30 Or “in righteousness and holiness which is based on truth” or “originated from truth.”
NET note #30 suggests “righteousness and holiness which is based on truth“. Three verses earlier in verse 21, KJV says “If so be that ye have heard him, and have been taught by him, as the truth is in Jesus:”
To summarise what I got from this:
The new man is (KJV) / was (YLT) / has been (NET) created in God’s image (NET) / after God’s likeness (ESV). Eph 4:24 explains that “image/likeness” refers to God’s Righteousness and Holiness. The process of creation (of the new man) in God’s image involves renewing “the spirit of our mind” in knowledge of the truth.
John 18:37 KJV
(37) Pilate therefore said unto him, Art thou a king then? Jesus answered, Thou sayest that I am a king. To this end was I born, and for this cause came I into the world, that I should bear witness unto the truth. Every one that is of the truth heareth my voice.
Appendix — Scripture passages pertaining to “the truth”:
John 8:31-36 KJV
(31) Then said Jesus to those Jews which believed on him, If ye continue in my word, then are ye my disciples indeed;
(32) And ye shall know the truth, and the truth shall make you free.
(33) They answered him, We be Abraham’s seed, and were never in bondage to any man: how sayest thou, Ye shall be made free?
(34) Jesus answered them, Verily, verily, I say unto you, Whosoever committeth sin is the servant of sin.
(35) And the servant abideth not in the house for ever: but the Son abideth ever.
(36) If the Son therefore shall make you free, ye shall be free indeed.
John 14:6 KJV
(6) Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.
2 Corinthians 5:17-21 KJV
(17) Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new.
(18) And all things are of God, who hath reconciled us to himself by Jesus Christ, and hath given to us the ministry of reconciliation;
(19) To wit, that God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them; and hath committed unto us the word of reconciliation.
(20) Now then we are ambassadors for Christ, as though God did beseech you by us: we pray you in Christ’s stead, be ye reconciled to God.
(21) For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him.
2 Timothy 2:25-26 KJV
(25) In meekness instructing those that oppose themselves; if God peradventure will give them repentance to the acknowledging of the truth;
(26) And that they may recover themselves out of the snare of the devil, who are taken captive by him at his will.
2 Timothy 3:15-17 KJV
(15) And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.
(16) All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:
(17) That the man of God may be perfect, throughly furnished unto all good works.
2 Thessalonians 2:10-14 KJV
(10) And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved.
(11) And for this cause God shall send them strong delusion, that they should believe a lie:
(12) That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
(13) But we are bound to give thanks alway to God for you, brethren beloved of the Lord, because God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief of the truth:
(14) Whereunto he called you by our gospel, to the obtaining of the glory of our Lord Jesus Christ.