This may be of some help to you.
https://calvinistinternational.com/2015/04/09/calvin-on-posture-in-worship/
We are not gnostic. Our bodies matter and what we do with our bodies matters. I can't remember who quoted him, but I once heard someone quote Calvin as apparently saying something to the effect of "we lift our hands, that our hearts may be lifted with them."
This doesn't mean that hand raising or any other posture works
ex opere operato. But in every context, not just in worship, posture, body language, etc. matters because it reveals something about our heart, or will inevitably effect our heart. I am not saying that we should require folks to lift their hands during worship or anything to that effect. But, especially when I don't
feel like worshipping God, lifting my hands in worship to God will often help my heart to follow suit.