[Iscool]

If Christ got a fully sinful human nature, from his fully sinful mother then how could he be without sin?

Because his father is/was God...Jesus in the flesh had the proclivity to sin...Had he not, he wouldn't have been fully man...Jesus would have been God just walking around with a covering made of flesh instead of a sheet...

[BenKenobi]

Then he wasn’t sinless because he suffered from Original Sin. Adam’s curse.