Does nature or nurture determine a person’s destiny?

Come, thick night,
And pall thee in the dunnest smoke of hell,
That my keen knife see not the wound it makes,
Nor heaven peep through the blanket of the dark,

The reason why i decided to choose this passage is because it caught my eye when Shakespeare used such powerful metaphors to emphasize the meaning of this passage. What really caught my eye was when he says: Nor heaven peep through the blanket of the dark. This caught my eye because in the medieval times God or religion was such an important part of those times and to do something that evil and using heaven as a reference is fairly risky. To me this part of the passage means that there are evil people in the world who really do kill to get what they desire most and they don't regret it because its what they want and nothing can stop them now because they killed them. I think that this is important because it shows that some people are mental and think that the only way to get their way is to get rid of the person to get what they want. This part is relevant to the play because it shows how evil and inhumane people could be to get what they desire most.
Nor heaven peep through the blanket of the dark,