I think this song's about the human condition. Greg is talking with and about all of us.
In the very first line I believe there's a reference to the Arthurian legend, he's describing the mythological Avalon as he imagines it, it's a new day, the sun's rising, and he opens the song with this powerful and short description we can all visualize clearly.
Then, here we have the human race, small, tiny and feeble just like "particles of sand" brought roughly into this world with no clue at all, not knowing what to do, who to trust, and who we exactly are (3rd line). Then, "The grains sift coarsely through the hour glass" which perfectly portraits, in my opinion, the bewilderment people feel, dragged around by an unknown force they're not able to control nor understand ("coarsely" is a key word, it explains how this force is completely casual and it's not like a thinking entity, but it could also refer to humans themselves, the big part of them is coarse and incapable of trying to figure things out, they live their lives without thinking) and they finally reach the bottom of the hourglass like defeated victims, as they die. Pure nihilism. But then there's the chore, and there, like in other BR songs, Greg contradicts the first verse, as if he wanted to say "okay, maybe the world's like that, but you have a choice. Stop complaining about the past and put your doubts away, maybe if you try you'll be able to find your Avalon" (that could be obviously interpretated as your own happiness, as Walk Away said, according to the Arthurian legend Avalon was a magic and peaceful island of the blessed, a sort of paradise, or a purpose for your life anyway). In fact the first line of the second verse talks about the paved road to paradise, which is not easy to find though, because in our life we have to deal with sorrow, pain (physical, the medicine, and mental) and lies, (medicine amnesia and lies could represent the elements with which we usually face our problems and the suffering). Then we have again the grains in the hourglass, but now they're our time that's running out, and they are not longer tiny, but heavy as boulders that pound on our brain, metaphorically our concern and troubles. And now, because of this pain, everything seems terrible and empty, even the things we did for fun, that once we found amusing. The song started with the dawn of a new day, in the final we find the twilight and the shade that now envelopes everything: birth and death, with our/painful/growth in the middle. You've been the one to choose his destiny, and at the end the story you'll tell, your story, is the one that you wrote yourself. The very last line is negative though, the "mortar" (our world or our soul?) under the shell is siled and decayed.

Well...I really like this song :)

I think that everyone is trying to disect this song, line by line, which for the most part is never really needed for a bad religion song. Its a composite, a feeling, a poem. The sum is much greater than the parts.

This song is about not being happy with your present situation, or whatever aspect of your life that may be. Change is hard. "I wish that I could tell you that it's easy....."

The past cannot be changed. All you can do is look forward, trudge on. Only you can find your Avalon. It ain't gonna find you.

I believe Walk Away hit it right with that interpretation. While I'm not going to deconstruct the song (or at least parts of it, the way Walk Away did), I'd like to add a few interpretive points myself.

I believe this song conveys a sort of mood or feeling that strikes a lot of people when the reach a certain age in their lives; a mood or feeling caused when someone enters into an extended state of reflection concerning the life one has lived. This state of reflection may come and go, and last anywhere from mere seconds, to minutes, to days and weeks. It's the sort of reflective state that often precedes- for example- what some like to refer to as a "midlife crisis," however, I do not believe that this song is about a midlife crisis, as much as it is about the wave of disappointment that often sweeps people during this reflective state; disappointment concerning the life one has lived, and how (this person experiencing this feeling) it hasn't culminated to what one deems an 'accomplished' life; a life lacking merit.

At this point, people (in their realized state of depression, resulted from that state of reflection) will begin to think that their lives have been lived wrong, or maybe even if it's a state of nostalgia, they wish that they could go back and change things they regret having done (or maybe that they hadn't done earlier, in terms of both time and place). Here, they feel trapped by time, including by their own age, and that there is virtually nothing that will change that.

Graffin, in Avalon, who writes from an obvious understanding of this feeling of a wasted, or unsatisfactory life, instructs such people to -basically- "suck it up," or "bite the bullet" and construct a life worth living for oneself... that only you are responsible for your own happiness, and that dwelling on the past is only going to delay that act of creating a life worth living for yourself; finding your Avalon. He's not criticizing the initial feeling or mood itself, only saying that one cannot stay disappointed and depressed forever, for it is something we, as humans, all go through.

I see this as a counterstatement to the often proclaimed "Life is futile" even when life is rough and seems to be futile. There is purpose in the end, and that purpose will be realized in the future.

This song is about how people which have an obscure or criminal past tend to be terrorized by these memories

This song advises not to be too bummed out but rather move along and strive for utopia.

This song is about time and our lives, and how we have to find our own personal salvation in a world where there are so many ideas of what is right or wrong, especially religiously.

Avalon is a major part of Arthurian legend, where Excalibur was forged and where Arthur eventually goes to "heal" from his wounds, although many see it as a place he went to die.

From this context, Avalon is our beginning (as drawing the sword from the stone was for Arthur) and our end (like wise).

The first verse points out the isle of Avalon with the wind blowing in from the sea, which is our world. We're brought into the world without a real direction, and time still continues to pass. Eventually, we'll all reach the same end and simply living a life tending to others ideas or desires without embracing our own will make this existence a "mundane" one.

The road to paradise refers to the way to reach Avalon, or what is beyond our own world. There is no easy way to get there, as even Arthur was wounded before he sailed for the island. We have to accept the reality of our physical world and of time which we have no control over. Humans need to contemplate what our actions really mean in the grand scheme of things.

The final verse simply describes the end of our days, and how what is here on the physical earth is all temporary and will decay in the same time we ourselves decay. All of our moments are subject to the constraints of time, past and present, and eventually future.

The chorus is of course a call for a person not to think about their past and what took place in it, but to push forward in finding a destination or goal to move towards.

That's just my 2 cents, if anyone else wants to chime in to try and clarify this a little more I'd love to hear it. This song is something I'm trying to wrap my head around.