If Jesus died on a cross, but then resurrected 'H'imself, what exactly did he sacrifice?

well mate, i think that that the whole sacrificed thing is that God asked him to do this to tell every one that he sacrificed his only son for us some way or other. the rising again is showing that he is the son of God and that God is omnipotent. don't keep me to this as i didn't do too good in R.E and im a Christian but don't believe so much in all this:)