I asked for the thoughts of long-time blog-neighbor Martin LaBar because he has written about similar subjects. He was kind enough to respond at length:
On what makes a blog Christian:
- A Christian blog must glorify God
- A Christian blog must be excellent
- A Christian blog treats readers, commenters, sources [and, I'd add, opponents] the way the author would want to be treated, and the way Christ would treat them
On what makes a sermon Christian:
A Christian sermon is a discourse, relating to or derived from Jesus or Jesus's teachings.
Many thanks to Martin for lending some insightful thoughts. What would you all add? Do you all struggle with similar thoughts and questions?