DND_Reborn
The High Aldwin
Strictly RAW it isn't a point of disagreement...The point of disagreement is whether the cleric hit you or the spiritual weapon and that does very much matter.
If you insist on answering that question: the cleric DID hit you with the spiritual weapon as a melee spell attack, which is why the roll is made using the clerics spell attack modifier.
It doesn't matter that the cleric wasn't actually wielding the weapon when the cleric hit you with it.