What is the best and cheapest light?

On my own, I am darkness, a black abyss. But, Life brings me light with its gentle kiss. I am quiet and cold, but warmth I can hold. Alongside beauties and wonders, sights to be told. My surface may be bare, this I’m aware. But, beautiful secrets I am eager to share. My mouth so large, I swallow you whole. To be in my belly is your goal. What may lie within can drive men to sin. Greed and desire, gluttony’s kin. For some, I am fear. For others, hope. My perception shaped from life’s scope. From the earth I have come, and forever will stay, even if parts of me crumble away. What am I?