If a slave disobeys a master, there are "consequences" of that as well. "You can believe whatever you want, but if you believe anything different from this, I will torture you forever and ever," is as tyrannical a statement as has ever been uttered.
I didn't say it was a good choice!
A slave will be forced to do things they don't want to. A slave will not be allowed to do whatever they wish, they will be stopped from doing things the slave master doesn't want.
In Christianity, (again by my understanding) no one is stopped from doing anything. If you disbelieve, if you sin, god doesn't levy some punishment and then you continue.
Like I said, the idea of eternal punishment is incompatible with the idea of a loving, merciful god IMO. I'm completely on board with that argument.
Really? Incompatible you say?
Let's flip this around and see what you think.
You have two children, you love with all your heart. You want to do everything for them, but you want them to love you back and you want them to choose to love you completely of their own choice. So you tell them, they can have your help if they ask you to. Your one rule to show they respect and love you? Obey your house rules which are very basic stuff that boils down to respect their sibling and others as well as yourself. If they won't obey the rules, they must get out.
The first child says okay, and goes off to do what they want around the house. They obey the rules, and ask you for help when they need it. Generally, the keep on being a good child to you and their sibling and others.
The other child though... well, they don't care so much for treating their sibling well. They start asking you to take things from their sibling because they want it instead, and they're not nice about how they ask either, showing a lack of respect. The more you chide them, gently for being so rude and demanding such requests from you, the more angry they get at you and start disrespecting you, calling you names, and finally denying your right to be in control of your house. Their apex of insults is saying they demand you get out of their life and never speak to them again. Of course, they will continue to reside in your house and accept all the privileges that come with it, without thanks.
Now, when the time comes that they become adults and you must move on. You now have to choose whether or not you are going to allow in your new home a child that obviously hates you despite your best efforts short of directly controlling them, or not? You know full well they cannot survive without you, but their hatred for you is so strong, they wish you dead and maybe... JUST maybe, would try it too.
Would you bring that grown child behind to their own doom, or threaten your existence or that of the child who loves you? Is your love such that you would allow yourself to be destroyed for someone who hates you so completely and would destroy everything you created given the chance? Or is it such that you would give them the life without you, knowing full well, while they don't, that they will perish?