The "One" god of Christianity comes more from Neoplatonism than Judaism. The Neoplatonic Oneness, which was washed out in various times in Christian history, is fully commensurable with contemporary science. Oneness can be experienced as the common mystical experience of "we are all one, man!" But for Neoplatonists, it only made sense that the ineffable and impossible to fully understand "One" was the origin of the universe and the basis of divinity.
This notion of Oneness is different from typical conceptions of the one god as a person. It is not. To understand true, original Christianity, one must reject the idea of personhood -- god isn't a person (and actually, neither are we--it's just a useful illusion)
In a nutshell: in the beginning of time, there was the Oneness and the emanation from the Oneness, which was known as the Logos. It makes sense here to think big bang: the whole universe in a single point. But from there, the emanations, the logos built everything else. The emanations can return to the Oneness through the creation of new wholes and harmonies (think molecules, stars and solar systems -- onenesses made of parts). This wholeness/harmony is the source of divine goodness. Here's the Christian part: when a person believes in the Logos they have eternal life because they recognize that their life is part of the eternal Logos.
That's what Christianity was to early church fathers like Origen or Clement. I forgot to mention -- Jesus was described as the incarnation of the logos.
Fun fact: Logos is equivalent to "Dao" in Daoism.
So, How'd I do? Are you more open now to the mysteries of Christianity?