Jesus did not die as our Substitute; he died as our Representative. He did not suffer, die, and rise again *instead* of us. All of us will suffer, carry our crosses, and die. But we must choose to do so in Christ. Because if we are joined to Christ, then we will likewise be raised *with* him and *in* him.
There is no Christmas without Jesus being born of his human mother, who of her own free will said, "Let it be done to me according to your word." Mary's central role in our salvation must not be undermined.