No doubt

Doubt thou the stars are fire,
Doubt that the sun doth move,
Doubt truth to be a liar,
But never doubt I love.

--Hamlet

In the strictest sense, stars really aren't "fire." Trust me, I'm an astronomer.
Also, the sun doesn't move, the Earth moves around the sun, so it only looks like the sun is moving.
As a wise man once said, many of the "truths" we cling to depend greatly on our own point of view...

Thus, what am I left to conclude about your love?