This Bible contradiction is from the Skeptic's Annotated Bible.

Verses

Sitting.

Mark 16:5 View context

And entering into the sepulchre, they saw a young man sitting on the right side, clothed in a long white garment; and they were affrighted.

John 20:11-12 View context

But Mary stood without at the sepulchre weeping: and as she wept, she stooped down, [and looked] into the sepulchre,

And seeth two angels in white sitting, the one at the head, and the other at the feet, where the body of Jesus had lain.

Standing.

Luke 24:3-4 View context

And they entered in, and found not the body of the Lord Jesus.

And it came to pass, as they were much perplexed thereabout, behold, two men stood by them in shining garments: