Genesis 1:26 says, "And God said, Let Us make man in Our image, after Our likeness...." By comparing Genesis 1:27 with Genesis 5:1, we see that He did what He declared He would do; humans were originally created in God's image (v. 1:27) and likeness (v. 5:1). Mankind was originally like Jesus; we were sinless, or in other words, righteous beings. But when Adam sinned, he ceased to be like God, and while we are not specifically taught that Cain and Abel were born in God's image but not in His likeness, we see that was the case for Seth. Genesis 5:3 says, "And Adam lived an hundred and thirty years, and begat a son in his own likeness, after his image; and called his name Seth."
Evidence that humanity no longer exists in both, the image and likeness of God, is found in the Apostle Paul's description of what Jesus did in order to become like us. He wrote:
"Let this mind be in you, which was also in Christ Jesus: Who, being in the form of God, thought it not robbery to be equal with God: but made Himself of no reputation, and took upon Him the form of a servant, and was made in the likeness of men: and being found in fashion as a man, He humbled Himself, and became obedient unto death, even the death of the cross" (Phil. 2:5-8).Jesus was the "image of God" (2 Cor. 4:4); the "image of the invisible God" (Col. 1:15); and God's "express image" (Heb. 1:3). But notice that we are not told that He was in the likeness of God; that is because He "was made in the likeness of men" (Phil. 2:7).
The "metamorphosis" that must take place begins with our being born again of the Spirit, when we place our faith in Jesus as our Lord (Jn. 3:3-8; Rom. 10:8-13; etc.). The Word says that then God begins a work in us to make us into the likeness of Jesus (Rom. 8:28-29; 1 Cor. 3:9; Phil. 1:6; Eph. 2:10; etc.)! Ironically, even though the transformation may be helped along by our cooperation (Rom. 12:1-2; Eph. 4:23; etc.), it will not be completed until we have departed this world. The Apostle John wrote in 1 John 3:2:
"Beloved, now are we the sons of God, and it doth not yet appear what we shall be:
but we know that, when He shall appear, we shall be like Him;
for we shall see Him as He is."