I generally think that religions deal with eternity precisely to not have any unanswered questions. If there was a time before God existed then there would need to be a reason for God to be brought into existence and an explanation would be needed as to how god was created. It also (by christian first-cause argument logic) implies that there was another being that created God, meaning God is not the most powerful, there is or was some supergod that created him. Even then you've need to answer where the supergod came from and so on. Saying god always existed is an easy way out of this problem, something that has always existed does not need, and negates the posibility of something before.

In terms of a scientific view of the start of the universe, I'm not up on my cosmology but the explanation that makes the most sense to me is that time exists within the universe, it is another dimension (like the 3 we move around in) so there was nothing before the univerese as 'before' needs time but time only exists once the universe exists. Without time there is no cause and effect thus nothing needed to cause the universe, infact nothing could have caused the universe.

Naturally that doesn't explain why the universe does exist, but it does explain how there can be no before and no cause.

Nobody is going around saying "because infinity exists, this book written by infinite inspiration is literally true and therefore you must not have pre-marital sex or be homosexual or vote democrat, and if you don't believe in infinity, you're going to hell."

Allow me to clarify: I'm saying your argument is a false analogy, Wavefreak.

Nobody is arguing that infinity has an external physical existence apart from the concept.  The token is used in the formal system of mathematics, but doesn't go beyond that (into things like, for example, moral questions or questions of where souls spend eternity).

This makes the analogy "belief in infintity = belief in god" a false analogy because of the key difference in the terms.  

Were that the analogy I was trying to make then you would be correct. But you are making an analogy that isn't there.

The original question was:

What I can't get over is why does a religious belief structure, would leave such gaping holes in the system? Why is there are always "eternity" and unanswerable questions?

First, this question can't be asked or answered without first assuming, at least temporarily, the existence of god.

Second, the question is about the inclusion of eternal existence as a property of god and why it is relegated to a category of un-answerable questions.

My analogy points out that we accept infinity in mathematics without knowing exactly what it is or how to get there. But it is a necessary concept to make parts of mathematics work. We aren't required to count to infinity to make use of it as a concept. And if we ask is there anything larger than infinity it is considered an odd question. Even though it has been shown that certain infinite sets are "larger" than others, there is still a largest set (last I recall, it is an open question if there are still "larger" sets yet to be discovered). The point to all this is that our understanding of infinity in mathematics is not complete, yet we accept it as a necessary property.

Moving on to my analogy. Again you cannot even ask the question without for a moment accepting the existence of god, so this is not a claim for that existence. My claim is that assigning the property of eternal existence to god does not require a full understanding of what eternal existence means any more than we are required to have a complete understanding of infinity in mathematics before we can make use of the concept.

Whatever your worldview, I think you still need something "eternal and uncaused" from which to start. So to each his own:

- Christian: God

- Buddhist: samsara

- Atheist: the universe or reality or energy (a.k.a. something we figure out with science)

So eternity is an axiom that everyone has to deal with.

The only way to get rid of the axiom, as far as I know, is to say we live in this causal universe made of space-time which all began at the Big-Bang and phrases like "before the Big-Bang" "what caused the Big-Bang" are meaningless because there is no time and causality to talk about. 

Human conceptualization.

I know, you want something more basic than that.

My answer would be: the relationship is not causal, but interconnected.... a triangle isn't 'caused' by three sides, it is a two dimensional object with three sides.

If 'eternity' were an axiom, it would be a necessary idea born of a human mind's attempt to contemplate matters of time. I.e. it would be part and parcel of one's concept of time.

  (I leave aside whether we are actually discussing an actual axiom here... not sure if 'eternity' is an axiom...)

The argument goes that we exist in a universe in which time always was and is and as such time has no beginning.  I read about this idea of infinite time and hear people propose it, not infrequently, as their explanation of why the universe exists, (ie. it never did 'not exist' - case closed).  To say time always existed and there always was time, means that time is 'travelling' forward from 'a point' (metaphor accepted) of infinity (obviously in the past).   It seems axiomatic to me that you cannot reach the present from an infinite past.  As time travels forward, 'marches on' etc. etc. - no matter how 'close' it may come to reaching the present, there is always an infinity of time drawing it into the past away from the present time, the present moment,  in which we exist.  If our time came from infinity then the present time would not exist and, moreover, we would not exist to have this discussion.  Starting from a 'place' (metaphor accepted) of infinity, time would never reach the 'big bang' in the first place, or even an infinite series of big bangs (whatever that means!). 

I don't see why an infinite past should be assumed impossible.  People say that if there's an infinite amount of time in the past then we would never reach here, because any amount of time that passed would still not get us here.  But what they hide is the "finite" implied in one key term.  A case that actually creates a valid argument is to say that any finite amount of time that passed would not get us here.  But this is basically like saying "but if we only had a finite amount of past time, then we wouldn't have an infinite amount of past time."  While this is true, it hardly shows that an infinite amount of past time is a logical impossibility.

Moreover, people always fail to separate temporal history from causal history.  If the temporal displacement between cause and effect decreases as we go backwards along the chan (say, because the universe was smaller in the past and so cause-effect, which is limited by lightspeed, could occur more quickly), and if this happens in a precise enough fashion, then you can fit an infinite causal chain in a finite amount of time.  In a way, you could think of the time being like the interval (0,now], where the zero point isn't included in the interval.  Causes can occur at times now, now/2, now/4, etc.  Thus you have an infinite causal history without an infinite temporal history.  No first cause and no first moment, but yet a finite amount of past time.