Trying to think of analogies to use in my lecture today, and I thought this one is good.
Think of the early Christian debates about the divinity of the Son and Holy Spirit like the history of Microsoft Windows. Someone early on comes up with a pretty good idea (Windows 95), and the generation after them adds some tweaks to make it a little bit better (98). Then, someone comes along and has a really really bad idea (Millenium Edition). So, everyone comes together and they rework things, take bad ideas out and put good ideas in. Over all, the final product is not to shabby (XP- Nicaea). Then, nothing happens for a while. This is followed by another really really bad idea (Vista) which also went through major revisions (7- Constantinople?). Repeat ad nauseum.