The Resurrection of Jesus: Truth or Legend?

I have often referred to a jigsaw that builds a picture of the truth of who Jesus really is.  My jigsaw has at least a 1,000 pieces.  One piece of jigsaw in its own right could be very powerful in its revelation but will never be as powerful as the bigger picture.  Here is one of those powerfully revealing pieces of jigsaw:

"Now, brothers, I want to remind you of the gospel I preached to you, which you have received and on which you have taken your stand.  By this gospel you are saved, if you hold firmly to the word I preached to you. Otherwise, you have believed in vain.
For what I received I passed on to you as of first importance: that Christ died for our sins according to the Scriptures, that he was buried, that he was raised on the third day according to the Scriptures, and that he appeared to Peter, and then to the twelve. After that he appeared to more than 500 of the brothers at the same time, most of whom are still living, though some have fallen asleep. Then he appeared to James, then to all the apostles, and last of all he appeared to me." 1 Corinthians 15: 1 - 7

Why is this an important piece of the jigsaw?  Well because a number of my friends believe that Jesus' resurrection is a legend, that it was made up many years after Jesus died, in the same way of the legendary activity of say Robin Hood or King Arthur. A Muslim friend and some of my blog readers believe this to be so.

Here lies the unbeliever's problem:

• The first is the media used in this document: Paul is writing a letter to his friends in Corinth. Not primarily to boast about the Cross and Resurrection but to tick off his friends for their ungodly conduct and to show people how to conduct themselves in church.  Now I don't know about you, but I am not in the habit of (a) lying to my friends ('last of all he appeared to me') or (b) including legendary material as if it is real ... when I write to my friends.
• Reputable neutral (non Christian!) scholars believe that this letter was indeed written by Paul
• Neutral (non Christian!) scholars date the letter around AD 55 only 20 years after Jesus' death. This is in itself by definition doesn't leave sufficient time for 'legend' to be formed.

But the unbeliever's problem goes deeper! :

"For what I received I passed onto you as of first importance."

You see Paul wrote this letter 20 years after Jesus' death - but he quite clearly received those words in red in in the first quote even earlier - most certainly a number of years earlier!

See what Paul wrote in Galations:

Then after three years I went up to Jerusalem, to get aquainted with Peter and stayed with him fifteen days. I saw no other Apostles - only James the Lord brother. Galations 1:18 - 19

It is most interesting that  Peter and James are mentioned together as witnesses to the death and resurrrection and in the above letter to the Galations. Equally interesting is the Greek word 'historio' used in the Galations passage. 

"This word ... shows this was an investigative inquiry. Paul was playing the role of an examiner, someone who was carefully checking this out." (The Case for Christ: Lee Strobel)

Almost certainly the words in red in the first quote is an early creed given by Peter and James themselves. 

The only conclusion one can make is that this by no means can be considered as legend. Indeed this creed is an eyewitness account of the death and resurrection of Jesus.  This eye witness creed dates back to with a couple of years of Jesus' resurrection!