Sort of like he’s saying if I have to be a liberal to still be a Christian, I’d rather not be a Christian anymore. Am I reading this wrong?
Yes, but I surmise that rather than obeying the light that he had and living by faith as a servant to be used by God in prayerful dependence on Him and His leading and providential care and intervention, and placing problematic texts in suspension awaiting more light as he did so, then he became preoccupied with such in academia, and used this to choose the broad and easier path.
The journey in "marching to Zion" is not without obstacles, some serve:
https://tubitv.com/movies/507867/the-pilgrim-s-progress