This may be a valid answer to whether miracle stories are an obstacle to Christianity, however this does not include the impact miracles have upon atheists. We must take into account the fact that it is not only the Christian faith that experience miracles, Hume’s notion of a miracle do not include Islam, Judaism or any other major world, deist religion.
In David Hume’s criticisms of miracles, he outlined that evidence from the past supports the natural laws that reject a lot of miracles such as walking on water – however, yes we can agree that historically and scientifically it is impossible to walk on water, but surely this is the basis of the miracle itself! Hume thus contradicts his definition of a miracle as a “supernatural being” would defy the laws of nature to allow someone to walk on water – thus for modern people this supernatural being would strengthen the faith as, particularly in Christianity, if there is a figure such as Jesus who is able to walk on water, then it could act as a way of knowing it is physically possible as it demonstrated the power and nature of God. However, some sceptical Christians may agree that evidence from the past would create an obstacle to their faith as it weakens the bibles claims. In his third criticism Hume states that witnesses may not be well educated therefore the ‘miracle’ they witness may be fascinated by what they see and suspend their reason – this causes many problems as uneducated people’s claims should not be less valued as faith is not an expertise, somebody’s religion should not be devalued because they perhaps do not have a degree in philosophy. A major criticism which could correspond to the argument the question is putting forward is that the miracles of each religion dispute against all other religions and their miracles, and so even if a fraction of all reported miracles across the world fit Hume's requirement for belief, the miracles of each religion make the other less likely – making miracles themselves cancel out religion. Hume does however agree that miracles are a possible occurrence and despite his criticisms he notes the obvious popularity in modern times with the belief in them and that "The gazing populace receive greedily, without examination, whatever soothes superstition and promotes wonder."
Maurice Miles, in his work The Remaking of the Christian Doctrine, discusses the notions miracles as natural laws in relation to their inconsistency with the Christian faith. In his suggestion he thus rejects the possibility that God would directly intervene in the world thus he rejects miracles. Wiles believes he would not interfere (God) for a number of reasons; Firstly he stated God should not be seen as playing an ‘active role’ but instead believe God created the world as he wanted in its entirety, "the world as a whole is a single act of God." With this in mind, God would thus not undermine the natural laws to intervene and therefore conduct miracles, and a supposed omnibenevolent God would not perform such insignificant miracles yet let disasters happen: “even so it would seem strange that no miraculous intervention prevented Auschwitz the purposes apparently forwarded by some of the miracles acclaimed in traditional Christian faith seem trivial by comparison." This therefore suggests that miracles perhaps hinder Christianity as, for Wiles; they merely oppose God’s position. Wiles advises us not to completely reject miracles seen in the bible as these should be viewed as symbolic – to teach us of God and faith.
For Rudolph Bultmann all miracles are “Mythological”. By this term he means that miracle stories were expressions relevant to the question of existence that the universe faces. He believes modern science has eliminated miracles: “Man’s knowledge and mastery of the world have advanced to such extent through science and technology that it is no longer possible for anyone seriously to hold the New Testament view of the world” Thus Bultmann obviously rejects miracles and thus stories about miracles could be viewed as an obstacle to faith as they do not correspond with science thus cannot be verified. Perhaps we need to demythologise miracles in order for them to be slightly more believable without suspending belief on a whole.
Miracles may be seen as a complication in belief in faith as they defy all natural laws and go against science however Quantum Physics suggests that the universe is no longer seen to be governed by a set of constantly applied rules, as in the Newtonian system, therefore the laws of nature can be seen as more fluid and thus miraculous events are more easily acceptable. This allows for atheist miracles also as these miraculous events are not necessarily divine.