Sometimes God sends His grace and we experience it even if we have no faith. Like when God multiplied the loaves and fish to the croud ( ), or at the apriation at Fatima during the miracle of the sun and when everyone in the croud had their clothes immediately dried, or during the transubstantiation during each Mass… and numerous other was God sends His grace.
Frankly, God is ALWAYS sending us His grace faith or no faith, hoping we will accept it and gain some or greater faith.
The devil… was a murderer from the beginning [tricking souls into loving evil] and does not stand in truth, because there is no truth [goodness] in him. When he tells a lie, he speaks in character [seeming to be good], because he is a liar and the father of lies.