Concise Bible Dictionary:


From Anstey’s Doctrinal Definitions:

When man fell, he ceased to be like God morally. Hence, in his fallen state, man lost his likeness to God. Thereafter he is not said to be “in the likeness of God.” In fact, Adam’s posterity is said to be “in his own likeness” (Gen. 5:33And Adam lived an hundred and thirty years, and begat a son in his own likeness, after his image; and called his name Seth: (Genesis 5:3)), which implies that Adam passed on to his descendants his sin-nature, which he acquired in the fall (Rom. 5:1212Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned: (Romans 5:12); Psa. 51:55Behold, I was shapen in iniquity; and in sin did my mother conceive me. (Psalm 51:5)). However, even in his fallen state, man is said to be “in the image of God” (Gen. 9:66Whoso sheddeth man's blood, by man shall his blood be shed: for in the image of God made he man. (Genesis 9:6)). The fall did not absolve him of his responsibility to represent God. But sad to say, that image in man has been marred by sin. Man has not represented God properly in the creation.
When Christ came into the world, Scripture says that He was “the image of God” (2 Cor. 4:44In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them. (2 Corinthians 4:4); Col. 1:1515Who is the image of the invisible God, the firstborn of every creature: (Colossians 1:15); Heb. 1:33Who being the brightness of his glory, and the express image of his person, and upholding all things by the word of his power, when he had by himself purged our sins, sat down on the right hand of the Majesty on high; (Hebrews 1:3)). He was not “made” in the image of God (as man was)—He was that by virtue of who He was. Thus, He represented God perfectly as the Head of creation. However, Scripture does not say that Christ was “in the likeness of God,” as man was when God made man. The reason for this is that, when Christ walked here, He was not like God, He was God (John 1:11In the beginning was the Word, and the Word was with God, and the Word was God. (John 1:1)). Scripture does say that in coming into Manhood, Christ was “made in the likeness of men” (Phil. 2:77But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men: (Philippians 2:7); Rom. 8:33For what the law could not do, in that it was weak through the flesh, God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh: (Romans 8:3)). This does not mean that Christ took sinful flesh into union with Himself; He was not like man morally. This statement is referring to the Lord being in the likeness of men constitutionally—having a human spirit (John 13:2121When Jesus had thus said, he was troubled in spirit, and testified, and said, Verily, verily, I say unto you, that one of you shall betray me. (John 13:21)), a human soul (John 13:2727And after the sop Satan entered into him. Then said Jesus unto him, That thou doest, do quickly. (John 13:27)), and a human body (Heb. 10:55Wherefore when he cometh into the world, he saith, Sacrifice and offering thou wouldest not, but a body hast thou prepared me: (Hebrews 10:5)). Though a real Man, He was “sin apart” (Heb. 4:1515For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin. (Hebrews 4:15))—that is, without a sin-nature.
The good news is that God in grace has created a new race of men under Christ (2 Cor. 5:1717Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new. (2 Corinthians 5:17); Eph. 2:1010For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them. (Ephesians 2:10); Rev. 3:1414And unto the angel of the church of the Laodiceans write; These things saith the Amen, the faithful and true witness, the beginning of the creation of God; (Revelation 3:14)), wherein both likeness and image are regained. Christ’s “many brethren(believers) in the new race can now exhibit the moral features of God and thus represent God on earth properly (Rom. 8:2929For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren. (Romans 8:29); Heb. 2:1111For both he that sanctifieth and they who are sanctified are all of one: for which cause he is not ashamed to call them brethren, (Hebrews 2:11)). The epistle to the Ephesians focuses on “the likeness of God” being displayed in this new race (Eph. 4:24-3224And that ye put on the new man, which after God is created in righteousness and true holiness. 25Wherefore putting away lying, speak every man truth with his neighbor: for we are members one of another. 26Be ye angry, and sin not: let not the sun go down upon your wrath: 27Neither give place to the devil. 28Let him that stole steal no more: but rather let him labor, working with his hands the thing which is good, that he may have to give to him that needeth. 29Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace unto the hearers. 30And grieve not the holy Spirit of God, whereby ye are sealed unto the day of redemption. 31Let all bitterness, and wrath, and anger, and clamor, and evil speaking, be put away from you, with all malice: 32And be ye kind one to another, tenderhearted, forgiving one another, even as God for Christ's sake hath forgiven you. (Ephesians 4:24‑32)), and the epistle to the Colossians focuses on the fact that the new race is “renewed in knowledge after the image of Him that created him” (Col. 3:1010And have put on the new man, which is renewed in knowledge after the image of him that created him: (Colossians 3:10)). Thus, the new race under Christ has regained what the old race lost under Adam.