You may be uncomfortable with the idea that God uses a section of the firmament as a movable platform like a giant cosmic surfboard. We get it, this is a deep end and we went off it. It's what we do.
We use multiple lines of investigation including scripture, empirical observations, theoretical models, and physical evidence to deduce the presence of a sphere of crystal on the edge of space.
Praise ye the LORD. Praise God in his sanctuary: praise him in the firmament of his power.
One of our favorite ways to study the Bible is to follow a doctrine through from the first time it's mentioned to the last. This is a great way to develop understanding of the doctrine in the broad narrative of scripture.