For I delivered to you first of all that which I also received: that Christ died for our sins according to the Scriptures, and that He was buried, and that He rose again the third day according to the Scriptures, and that He was seen by Cephas, then by the twelve.  After that He was seen by over five hundred brethren at once, of whom the greater part remain to the present, but some have fallen asleep. 

1 Corinthians 15:3-6   (NKJV)