'Lifted Up' in the Bible

As the snake was lifted up by Moses in the waste land, even so it is necessary for the Son of man to be lifted up:

So Jesus said, When the Son of man has been lifted up by you, then it will be clear to you who I am, and that I do nothing of myself, but say as the Father gave me teaching.

(These things were not clear to his disciples at first: but when Jesus had been lifted up into his glory, then it came to their minds that these things in the Writings were about him and that they had been done to him.)

And I, if I am lifted up from the earth, will make all men come to me.

Then the people in answer said to him, The law says that the Christ will have life without end: how say you then that it is necessary for the Son of man to be lifted up? Who is this Son of man?

I am not talking of you all: I have knowledge of my true disciples, but things are as they are, so that the Writings may come true, The foot of him who takes bread with me is lifted up against me.