Scientists such as Victor Stenger et al., hold that the existence of a God like that worshipped by the big three monotheisms (Judaism, Christianity, and Islam), can be disproved. These men point out certain known facts about these gods. It is well known, for example, that in the Hebrew Scriptures, the Christian Old and New Testaments, and the Islamic Quran, that God is one known for creating miracles on a regular basis, especially in the Hebrew and Christian Scriptures. According to these religious sources God cannot keep his divine nose out of our business. He is always intervening in obvious and visible ways, unmistakeable ways.
The majority of these non-believing scientists point out the strange coincidence that as science progressed ever more and more that miracles have ceased to be in evidence. God was supposedly always actively intervening in the Old and New Testaments, right up on through the middle ages and until toward the end of about the 17th century. Roman Catholics still claim that miracles happen all the time, but such is not really documented under controlled conditions.
In his book "God: The Failed Hypothesis", Professor Stenger speaks of three types of miracles that can be generally identified: Violations of established laws of nature; Inexplicable events; and Highly unlikely coincidences. He speaks of miracles as being cosmic phenomena that would forever defy material expectations, and gives as an example a new planet suddenly appearing in our solar system. He is not talking about a planet that drifts into our system while no one is looking, but a planet that appears out of nothingness in violation of energy conservation.
What the Professor is basically saying is that if a deity such as that spoken of in the Bible existed there would be unmistakable evidence of it that could be empirically examined and tested. The God of the Bible is not one for hiding his tracks as the Bible makes plain. Now doctor Stenger does not rule out the existence necessarily of a deist type, non-intervening deity, but he says that such a god would be of no interest to the three monotheisms, and, in fact, if such a deity did exist we would have no way to either confirm or disconfirm it, so it would basically be pointless to even speculate on the existence of such a deity as this.
So, while some kind of non-intervening deity is not ruled out with 100% certainty, the deity of the monotheisms are most definitely ruled out as existing.