"What did Christ sacrifice if he is with God in Heaven?"
Jesus Sacrificed his Son: the Man Christ Jesus.
John 15:12-13King James Version (KJV)
12 This is my commandment, That ye love one another, as I have loved you.
13 Greater love hath no man than this, that a man lay down his life for his friends.
1 John 3:16King James Version (KJV)
16 Hereby perceive we the love of God, because he laid down his life for us: and we ought to lay down our lives for the brethren.