Pointing to a lot of errors made by humans and even so-called "Christians" throughout history says nothing about the veracity of Biblical Christianity. It is a standard none of us can meet.

To be sure, we are dealing with a needle of truth in a haystack of lies - one constructed by satan, "the father of lies" as Jesus put it.

We know more about satan and Hell from what Jesus taught than any other source. That's another great reason to take it seriously.

At to your point about free will. God is recruiting people to serve in His government and become members of His family. He needs people who will be loyal and faithful and trustworthy with that kind of power. So he sets up the situation we find ourselves in. Plenty of free will opportunity to walk away and join satan's side. Since God has made it clear what joining satan means, whose fault is it if that's the choice you want to make?

Again, choose your side. Hell is not a threat, it is the default consequence of not choosing to accept a position in God's kingdom.