Mercy asked:
What are David Hume’s contributions to the debate on God, especially her/ his/ its attributes of first cause?
Answer by Tony Fahey
Religion holds that the world operates on cause and effect and that there must therefore be a First Cause, namely God. In Hume’s world view, causation is assumed but ultimately unknowable. We simply do not know there is a First Cause, or a place for God.
In his Natural History of Religion Hume argues that religious beliefs arise from Man’s propensity to attribute anthropomorphic attributes to unseen forces. In his Dialogue Concerning Natural Religion, he shows how the Argument for Design cannot survive careful application of the scientific standards.
According to Hume, God is a complex idea which we cobble together in our minds. Whilst he accepted that the degree of order evidenced by the universe suggests some kind of designing intelligence, he rejected the notion that this was proof of the existence God on the grounds that human reason was insufficient to provide such evidence.
Hume is generally believed to be an atheist, particularly given that his Dialogue concerning Natural Religion, notwithstanding its polite and careful ambiguity, was deemed to be powerfully anti-theistic. However, since he argued that the existence of God could neither be proved nor disproved, some philosophers, such as Jostein Gaarder, suggest that is more likely that was an agnostic. However, since Hume died without holding out any hope of an afterlife it seems there is no substance in this argument. Indeed, in his book, The Book of Dead Philosophers, Simon Critchley tells us that Hume, responding to arguments in favour of the immortality of the soul, said, ‘By what arguments or analogies can we prove any state of existence, which no one ever saw, and which no wise [no way] resembles any that was ever seen’. (2008, p.175)
Ask a Philosopher 
david Hume did not doubt cause and effect, he just said that some things are unknowable, imponderable. and that a final cause, the unmoved mover, is an imponderable.
Every thing I do has cause and effect,if I put food in a pot it cooks and we eat it! If I put gas in my car it keeps going down the road.If you walk up and slap someone you will probably cause a fight! David Hume doubts cause and effect simply because he wanted to disbelieve in a personal God. This doubt he has of cause and effect is probably the most known about thing in the universe,It could almost be called a law of the universe,but science would NEVER call it that! However I see it with my own senses every day. Why do you waste time cleaning your house or toilet or cleaning out your car??? because they get dirty! why do you cook food or go out to eat ??because you get hungry!!! David Hume is arguing the illogical! and He is wrong!