Can a Cleric lose their magic if they disobey their god/temple? Need advice for a ruling.

I am a DM for a D&D 5.5e. I want to guide my party to a new location. I don't want to make it feel like railroading, so I decided to send an order to our Cleric: "Your temple commands you to go here."

However, another player (a Sorcerer) said: "The Cleric doesn't have to follow this order."

I told them that if a Cleric ignores a direct holy order, their deity can stop giving them magic. In my understanding:

* Clerics are channels for divine power. They pray during a long rest to prepare spells, asking their god for magic. If they disobey or make their god angry, they lose that connection.
* Warlocks are different. Their patron gives them knowledge/secrets, so even if they break their pact, they keep the powers they already learned.

My player strongly disagrees. They say Clerics never lose their powers once they get them, even if their god dies or abandons them.

I don't want to spend 10 hours reading wikis and forums, so I am asking here: How does this actually work in the 5.5e rules and lore? Can a Cleric lose their powers, or is it completely up to the DM?

Thanks for your help!