Answer:
I weaken all men for hours each day. I show you strange visions while you are away. I take you by night, by day take you back. None suffer to have me, but do from my lack.
Though desert men once called me God, today men call me mad. For I wag my tail when I am angry. And growl when I am glad.
What is it something that you always have but you always leave behind?
I make you weak at the worst of all times. I keep you safe, I keep you fine. I make your hands sweat. And your heart grow cold. I visit the weak, but seldom the bold.
In the forest, this blends in just right, but every December it is covered with lights. What is it?
Brings the sky a lot closer.