On the Lord’s Supper, it matters what you believe the spiritual is.
It doesn’t seem to mean very much to you, but Jesus explains in John 4 that God Himself is spirit.
Can you explain the “physics”of that, then? Or of how God sees and how His eyes work, versus how ours do? Or the physics of the light that the Father and the Son will provide in the New Jerusalem, or of Heaven and our glorified bodies?
It’s not nothing to participate in the Lord’s Supper in remembrance of Him, which proclaims His sacrificial death for our sake, so that we can come alive spiritually and have eternal life. To consume it unworthily is to be in unbelief, denying what He’s done for us.
And here is where what saves us is clear, too, in terms of faith and works. Our eternal life is entirely dependent on His sacrifice, as the Lord’s Supper shows. He’s our one and only food for eternal life. We don’t provide any of it.
Jesus also actually could have given His disciples something of His actual body and blood to consume at the Last Supper, but He didn’t.
After the unbelieving left, Jesus then explained to His disciples that it was His words that mattered, as they believed Him.
Heck; HE didn't even tell the Doubting One to lick his fingers after probing HIS wounds!