The book of Revelation describes Jesus as "slain before the foundations of the earth":
All inhabitants of the earth will worship the beast--all whose names have not been written in the book of life belonging to the Lamb that was slain from the creation of the world. (Revelation 13:8, NIV)
What does this mean? The "angel of the Lord" who appeared to Moses is Jesus, as I understand the following verses:
Moses said to God, "Suppose I go to the Israelites and say to them, 'The God of your fathers has sent me to you,' and they ask me, 'What is his name?' Then what shall I tell them?" God said to Moses, "I AM WHO I AM. This is what you are to say to the Israelites: 'I AM has sent me to you.'" (Exodus 3:13–14, NIV)
In addition, Numbers 29:13 indicates that Jesus didn't have a human body before the foundation of the earth:
God is not a man, that he should lie, nor a son of man, that he should change his mind. Does he speak and then not act? Does he promise and not fulfill? (Numbers 29:13, NIV)
What does it mean for Christ to have been slain before the creation of the world?