For both Atheists and Theists of good will, the biggest impediments to understanding the First Way are (a) why the being it proves the existence of can be called a god and (b) how per se ordered causes are simultaneous. One can sidestep both of these concerns with a modified version of the First Way:
Everything in motion is moved by another
Every candidate for a first mover in nature is in motion.
The premises thus conclude to a mover that is (a) beyond nature and (b) joined immediately to whatever we understand to be the first mover in nature (Aristotle’s celestial sphere, Newton’s force, our mass-energy, etc.) We thus conclude to a supernatural mover that is causing motion in nature immediately and not at the end of a causal series. Because we’ve done away with the causal regress, we don’t have to deal with any of the distinctions or clarifications one has to make about causal regresses (e.g. the difference between a per se and per accidens series, the difference between being simultaneous and instantaneous, or the dizzying denial of infinity that so many get hung up on.)