Apologists do not just say the NT gives us multiple first-hand accounts of the resurrection of Jesus, they also assert that the first-hand nature of these accounts is “clear”. At least the more fundamentalist of them argue that way.
The gospel we today call “Matthew” contains testimony that Jesus Christ rose from the dead:
“And behold, Jesus met them and greeted them. And they came up and took hold of His feet and worshiped Him.”
(Mat 28:9 NAS)
Assuming for the sake of argument that Matthew wrote that gospel, who is the person responsible for testifying that Jesus greeted these woman after he died? Is it Matthew himself doing the testifying, or is he here reporting what somebody else told him, and how do you know?
You may say that assuming Matthew wrote it, then obviously the testimony to the resurrection in Matthew 28 draws solely from Matthew’s own eyewitness memories of those events.
But it ain’t quite that simple.
If you accept one of the popular views among Christian scholars, namely, that Matthew drew heavily from Mark’s text or other earlier sources, then it becomes nearly impossible to distinguish testimony in Matthew’s gospel that arises solely from his own eyewitness memories, testimony that Matthew received from other sources and chose to incorporate into his gospel, and testimony that is the result of combining Matthew’s eyewitness testimony with non-eyewitness testimony.
If you accept Matthian priority (that Matthew wrote before Mark or Luke did, or at least without using them or their sources) then the question of which parts of his resurrection story draw solely from his eyewitness memories, and which don’t, looms.
Sure, you can probably provide an answer to these questions, but is your evidence so good and your conclusion so utterly inescapable that it renders foolish anybody who hears your argument and yet refuses to take your side? Unless you meet that high burden, you do not have an evidentiary warrant to label as fools those who disagree with you. All you have a the unsupported speculation of certain biblical authors that insisted unbelievers are “without excuse”.