Why was Adam's body without sin at his creation?
Adam's body was without sin at creation because his entire being—body, soul, and spirit—was in perfect fellowship with God and under the Creator's control. His soul and spirit agreed perfectly with God, so his body had no opportunity to sin before the fall.
Les explains that when Adam was created, he was created with a body, a soul, and a spirit. His soul, which made up his personality—mind, will, and emotion—was in perfect agreement with the Creator, and his spirit had fellowship with the Creator; he walked with God in the garden. With all of this under the perfect control of the Creator, the body was without sin as well because it had not had any opportunity to sin. When Adam sinned, his whole personality became what Paul calls a sin nature, bent to sinning, and communication with God became dormant, not annihilated.