I was in a reading group 15 years ago on the topic, and cite one of the books in my piece linked earlier in the thread. I think the place to start is to look at how the creeds emphasize the incarnation and the ascension. Look at, and think about, how the Nicene Creed (the one I grew up reciting as a Catholic) asserts “begotten not made” and relentlessy insists on Jesus’ “one in being with the father.” Then think about how the creeds were to a large extent (or even completely in some cases) responses to errors (aka heresies) that were widespread and seen as threats. (Or maybe in some cases it’s more accurate to say that the creed asserted a newly emerging consensus on an orthodox position.)
Gnosticism, in general terms, is probably the biggest threat to Christian belief from within. (From outside, the biggest threat is the lack of credibility of Christians, and therefore of god’s claims about his influence on his people.) It is an ancient heresy, one of the first big crises of orthodoxy, and a rampant religious temptation in modern American Christians. You can hear it almost daily on this Forum, from believers and from some of those advancing heterodox claims. It’s basically the belief in secret knowledge, as opposed to public truth. One interesting thing about the ascension is not so much that it’s ridiculous to think that a person levitating into the stratosphere is “going to heaven” but instead the pains to which the NT writers went to establish the event as a public occurrence observed by many.
That was me rambling, sorry, and I apologize in advance for errors of emphasis re the history of creeds. Definitely worth learning about; for one thing, it puts American evanglicalism into sharp contrast with historical creedal Christianity, to the extent that some (including many Christian friends of mine) are willing to call evangelicalism false religion.