Fake news.
https://www.thegospelcoalition.org/blogs/evangelical-history/75-years-ago-today-c-s-lewis-delivers-a-sermon-on-the-weight-of-glory/
among others.
“Fake news.”
No, actually it’s true that it was a message and not a sermon. That’s why it is not based on a particular reading from the gospels. It’s not a sermon. It’s just a message. That’s how Anglican chapels for students often worked.
Again, this was an Evensong message, not a true sermon. Also, lay people can speak in Anglican churches from the pulpit but they need to be licensed to preach or teach. Was CS Lewis? I assume so, but this was not a sermon. It was just an Evensong message. It was not a sermon.