It seems that if He had no sin nature, He couldn't have sinned if He wanted to, and if He had no sin nature, that would mean He was not fully human.
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The sin nature of man entered the world through Adam. Therefore being born of a woman with the Father (God) the sin nature was passed. He was 100%man and 100% God so no he could not sin.
If Jesus was 100 percent human and humans have a sin nature than is makes sense Jesus was born with a sin nature, but lived a sinless life.
Darrell, the sin nature is passed down to every child through their father. Jesus alone was born without a sin nature because of His virgin birth which allowed Him to bypass the curse passed through Adam (Psalm 51:5, Romans 5:12).