Contradiction with Matthew 28:9
Matthew 28:9 describes Jesus appearing to Mary Magdalene and the other Mary, which differs from 1 Corinthians 15:5 that mentions he was seen of Cephas (Peter) first.
Matthew 28:9: And as they went to tell his disciples, behold, Jesus met them, saying, All hail. And they came and held him by the feet, and worshipped him.
Contradiction with Mark 16:9
Mark 16:9 states that Jesus appeared first to Mary Magdalene, contrasting with 1 Corinthians 15:5 that mentions he was seen of Peter first.
Mark 16:9: Now when [Jesus] was risen early the first [day] of the week, he appeared first to Mary Magdalene, out of whom he had cast seven devils.
Contradiction with John 20:14-18
In John 20:14-18, Jesus first appears to Mary Magdalene, differing from 1 Corinthians 15:5 that indicates Peter saw Jesus first.
John 20:14-18: And when she had thus said, she turned herself back, and saw Jesus standing, and knew not that it was Jesus.