I have an idea that maybe the "taking up serpents" thing means "casting out demons".
Why? There is plenty of demon talk in the Gospels. If the author meant "demons" he would have written "demons."
But it doesn't matter, because that part of Mark is not original to the text in any verifiable way. It is a later addition. Not to be trusted as historical or doctrinal.
That's disputed. It might be a part of the original, it might not be.
It's not really disputed, except perhaps by fundamentalists who start out their examinations with the belief that everything in the Bible is straight from God.
Virtually every major Bible translation brackets off that section of Mark.
Those translations never say that Mark's long ending was definitely an addition. They just say "This section is not included in 2 manuscripts" or whatever, and leave it up to you.
Why? If the spiritual realm is real, than why are demons/daemons/whatever a ludicrous concept?
Because if there is an omnipotent God, then how could there exist demons without his consent? And why would an all-loving God allow demons to possess people and cause them harm? This is not the question of why does evil exist in the world, but why would God create such beings in the first place? It makes no sense.
How would anyone know the answer to something like that? We have no idea what demons are or how they came to be. For all we know they could be fallen angels.
I don't know how you could believe Jesus is the Messiah and not believe in demons. Jesus himself believed in demons.
Let's be as accurate as possible. We don't know what Jesus believed. But the Gospel writers certainly believed in demons. That doesn't make them real.
Although we don't have writings directly from Jesus, we have records of what he said. So if he taught about demons, I don't think it's unreasonable to assume he believed in demons, too.
And frankly, "Messiah" is a loaded term. I believe Jesus was the Son of God, but by virtually every Jewish expectation of who and what the Messiah would be, Jesus doesn't really fit the mold.
Your view seems really inconsistent. Okay, so he's the Son of God.
He calls himself the Son of man, referencing Daniel, who is supposed to establish God's kingdom. He quotes the OT and clearly places his trust in the OT. He teaches eternal existence in either heaven or hell. But apparently, he's horribly mistaken and he got it all wrong.
What's so special about being the Son of God, then?