They believe his flesh was never blemished, his teeth were always pearly white, and his scent was like that of fine perfume from the time he was born to the time he was crucified. Practically, we know this wasn’t the case. Theologically, we know it couldn’t be.
For one thing, Jesus was simultaneously completely divine and completely human. On the divine side, he did not sin — His spiritual being was perfect — But the physical side of his existence, the human side, was not without blemish. It is absurd to think that a man could walk the earth for 33 years without ever getting dirty, without ever getting a bump or a bruise, or without ever having a hair out of place. It is also necessary that Jesus had the same physical ailments as you and I for the sake of his mission. Consider this:
How could he relate to the working class if he never had body odor?
How could he reach the farmers and shepherds if his flesh never knew dirt?
How could he be trusted by the lepers, if his skin was never wrinkled or scarred?
How could he let the blind receive sight, had he never had bags under his eyes?
How could he take diseases from dying children, if he himself had never been sick?
How could he tell the lame to walk, if his legs had never ached?
How could he feed the multitudes, if his stomach never growled?
How could he turn water into wine, having never been thirsty?
How could he have endured the flogging after his arrest, without any marks on his back?
How could he have actually died, had his body not been just like ours?
It was absolutely necessary for Jesus’ body to suffer the same imperfections as our bodies. He could not have related to the people, could not have understood them, and could not have had the compassion that He did, had His body not been made from the same flesh and tissue as everyone else’s.