Lincoln speech on the Bible?

[RJNorton]

I am suspicious of this speech. If Thomas Lewis were such a good friend of Lincoln's, and worked in an adjoining law office to Lincoln and Herndon, why was he not interviewed by Herndon in 1865? I would have thought Lewis would be an early and logical contact person for Herndon. If he were interviewed by Herndon, and he told about Lincoln's 1852 Bible lecture in the interview, then I would probably be more agreeable on this speech. But I am curious why there is no correspondence/interview with Lewis in Herndon's Informants.

Did Herndon consider him a poor source?

Or (possibly) did Herndon know Lewis' opinions on Lincoln and religion were different than his own and therefore purposely did not contact him?

If there were truly a full house for Lincoln's talk I would think some of the folks present were certainly among the Springfield inhabitants contacted by Herndon. if Lincoln really gave this Bible talk, why don't several people mention it? I really have doubts about this.