When a prophet or a "dreamer of dreams" comes along and tries to inaugurate a new religion or a new "gxd" and works supernatural miracles to prove his authority, it is merely a test.
No, no.
Yes, yes.
Point to the EXACT verse and it's wording to make your point about this new relion and this new god.
(I'm trusting the rabbis have written it down correctly.)
You have just quoted the relevant passage from Deuteronomy 13. What more are you looking for?
At any rate, it's Deuteronomy 13:2-6. Verse 4 explicitly says that any miracles worked by the prophet are a test from G-d. Verse 5 instructs the people to stay with the G-d Who brought them forth from Egypt and spoke to them at Sinai.
That's about as plain as you can get.
I guess I just have missed the NEW religion and the NEW god somewhere along the way.