Darwin was definitely in the thick of the academic world at the time, and there are proto-citations and references of friends and colleagues in his work (formal citations as we know and understand it weren't quite there yet- sometimes you just have to know the person they're referencing even if their name isn't fully mentioned).

His later work was definitely on a decline on his writing skills and styles, but he was still very sharp for the time. He was also lacking key elements of how hereditary evolution worked- such as the concept of genetics and inheritability as discovered by Mendel and others. On top of that was the proto-social evolutionary discussion where he did side with some people like Galton (his cousin) despite it being found wrong later on.

He did get mired in the religious/scientific (some overlap, some not) debate with people like Captain Fitzroy of the Beagle (a very interesting angle) and Wilburforce, who had his own brand of anti-evolution- a person who is very much at the center of this debate.

Wallace had his own interesting divergence from the group, Lyell came from geology, Huxley came from anatomy (a man very much in the scientific camp), Galton was all over the place (he was so very wrong in so many ways, but very much a genius despite it).

All of these men ran the gamut on science and religion, and it's not just a clear cut "we are scientists or religious people" scenario.

Darwin very much became the go-to symbol for evolution even while alive, but we also have to account for his massive lack of scientific data (Mendel as mentioned before, a few others) that's found in HS textbooks now. He knew it worked, but he didn't know the mechanisms for how it worked, and even that tripped him up on a few key elements far more than the religious issue.