Goodman Games

I run a 4th level Cleric in a campaign. I was hit with something, possibly a curse, by a demon that stopped my character from speaking. The Judge ruled I should go down one on the die chain (he was being really nice) to cast my spells. I could argue that Clerics could either be hit with this, or possibly not if they only need to recant their prayers in their head and not aloud. I don't care either way, I'm just interested in how other players feel about Clerics "magic". If your Cleric is muted should their magic be cancelled? I can honestly see it both ways but feel that Clerics need to have some sort of vulnerability. If they can't speak, maybe they can't pray? It's really rough, but are wizards in a different position? However I can see that since Clerics can still think they can just as easily pray inside their mind, without speaking, and perhaps still reach their god. It's a totally weird rules question but I hope I can hear some good opinions.

I guess I'm kinda stuck in the mindset of D&D where, some spells do require you to be able to say something out loud to cast them, so you'd be unable to cast those spells while you are muted.

The core book, unless I am completely mistaken, requires one hand free and the ability to speak.