Abrahamanic religions do not believe we are born in sin. According to Islam we are all born in fitra [having an innate human nature that leans towards belief in God]
http://en.wikipedia.org/wiki/Fitra
According to Islamic theology, human beings are born with an innate knowledge of tawhid, which is encapsulated in the fitra along with intelligence, ihsan and all other attributes that embody what it is to be human. It is for this reason that some muslims prefer to refer to those who embrace Islam as reverts rather than converts, as it is believed they are returning to a pure state.
The perfect embodiment of fitra was Abraham and Muhammad.
Narrated Abu-Huraira:
Allah's Apostle said, "No child is born except on Al-fitra and then his parents make him Jewish, Christian or Magian (Zoroastrian), as an animal produces a perfect young animal: do you see any part of its body amputated?"
- Sahih al-Bukhari, Volume 2, Book 23, Number 441