What is the evidence for a god/higher being/etc. existing? How does he/she/it interact with the universe?

There are hypotheses that the Chaos permanently exists and is the underlying fabric from which the current universe and all possible universes (past and future included) spring from as temporary nodes of stability. (Cf. especially QED theory, where everything that can happen does happen at the same time and the classic world comes from interference mass-cancelling.)
phys.org/news/2015-02-big-quantum-equation-universe.html
rorotoko.com/interview/20110309_bojowald_martin_on_once_before_time_whole_story_universe/?page=2

The first law of thermodynamics. There you go.

See pic related human understanding by necessity leads to the existence of God which is why atheism tends to avoid philosophy and atheists avoid looking at their axioms.

Attached: aqinas.jpg (2700x6826, 2.15M)

vorpal.us/2007/10/the-five-ways-of-st-thomas-aquinas-are-all-dead-ends/

The primal mover may not be necessary as proposes.

The Argument of the Unmoved Mover
This cosmological argument asserts that God must be the cause of all movement in the Universe. Aquinas contends that an infinite regress of movers is impossible, meaning that there must be an unmoved mover that initiated all motion - and that this mover is called God. One could just as easily call the first mover "Charlie", or any other preferred name, since the argument does not prove that the "unmoved mover" has any of the characteristics that are usually associated with the concept of God, such as consciousness, benevolence, omnipotence, or a proclivity to intervene in our universe. Far from proving that the Christian God exists, the most the argument can do is support a sort of weak deism - and even this is questionable, given that the "first mover" could just as easily have been the Big Bang as any preferred deity.

The Argument of the First Cause
This is practically a paraphrase of the Unmoved Mover argument above: same steps, same order, same leap of logic from common sense to assumptions about the nature of the universe, same special pleading for God. Unlike its predecessor, this argument does not make the questionable assumption that the natural state of things is not motion; however, it still makes the leap of trying to apply the "in-universe" concept of causation to something that is supposed to have existed before the universe began.

The Argument from Contingency
This argument for the existence of God is yet another variation on the first two, this time phrased around an explanation of why something exists rather than nothing. According to Aquinas, it is conceivable for the universe not to exist (meaning that it is contingent); thus, it must have a cause for existing. This cause must not be something that is also contingent, but rather some thing whose existence is necessary. And this is what he calls God. This argument suffers from the same issues as the first two argument in that it simply defines God as the original cause of everything, without any explanation of why this cause should have the attributes of Aquinas' preferred God rather than any other deity (or deities) or the Big Bang.

The Argument from Degree
Aquinas argues that there must be an ultimate standard of perfection to which everything else can be compared. Therefore, perfection must have a pinnacle, which he calls God. The main problem here is that the existence of a concept of a maximally perfect being does not prove that the being exists for real, any more than the pinnacle of any other positive or negative quality, such as smelliness, proves the existence of a real entity embodying this pinnacle.

The Teleological Argument
This argument is based on the premises that unintelligent objects, such as rocks, act towards an end (such as falling to the ground), but that they cannot do so unless they are directed. Aquinas' conclusion was that a single being with intelligence directs everything towards its end, and he called this being God. In addition to the questionable aforementioned premises, this conclusion also rests on the unsupported assumption that each individual object cannot be guided by a unique being.

A objection to the argument from first cause is that it suffers from special pleading. While everything in the universe is assumed to have a cause, God is free from this requirement. However, while some phrasings of the argument may state that "everything has a cause" as one of the premises (thus contradicting the conclusion of the existence of an uncaused cause), there are also many versions that explicitly or implicitly allow for non-beginning or necessary entities not to have a cause. In the end, the point of the premises is to suggest that reality is a causally-connected whole and that all causal chains originate from a single point, posited to be God. That many people using this argument would consider God exempt from various requirements is a foregone conclusion, but citing "special pleading" because finite causal chains are said to have an uncaused beginning is hardly a convincing objection.

A more pertinent objection is that, even assuming that there is a first cause, the argument utterly fails to address how we can know its identity. The assertion that it must be the particular God that the arguer has in mind is a complete non sequitur. Why not the deist God? Why not some kind of impersonal, eternal cosmic force? Why not shape-shifting aliens from another dimension? Why not a God that sends Christians to hell and atheists to heaven? Or maybe the simplest of all, why not the Big Bang as the first cause? There is nothing in the argument that would allow one to determine any attributes of the first cause.

Finally, there is nothing in the argument to rule out the existence of multiple first causes. This can be seen by realizing that for any directed acyclic graph which represents causation in a set of events or entities, the first cause is any vertex that has zero incoming edges. This means that the argument can just as well be used to argue for polytheism.