I'm a liberal (radical in some ways) and something between an agnostic and an atheist.

Religion as such is the curse of mankind.
That sums up its role in this stage of history.
A god of some sort that makes the universe conforms to science just as much as having a universe pop up out of nowhere. Try to prove their isn't a god. 
If there really isn't an almighty being who created the universe, then their obviously isn't any purpose to life, other than the one that you create yourself, even though you shouldn't be able to create your own reason for existence if their is no reason to exist in the first place.
Actually, this does not fit in with science at all, as scientific philosophy dictates to disbelieve everything without either theoretical or experimental proof. It may be impossible to prove the nonexistence of a god, but it is then equally impossible to disprove it as well. Unless experimental or mathematical evidence exists (neither does), the idea should be discarded.
The god thing isn't that much of a problem alone; it is this way that people think of a god as a "superhuman" with his own petty ambitions and one who interferes with human affairs. You can call the big bang god for all it matters, but this idea of a god who watches over people and rewards or punishes them is simply ridiculous. Also, the one important question remains: how was this "almighty" created? No religion ever seems to explain that, or even try to think about it, because then their whole dogmatic structure would fall to pieces.
Now, as for the idea of purposes, this had me thinking for quite some time about a year ago. First, nothing has to have a "purpose" except as seen through subjective eyes; causality can include random causes and can go back into history for a transfinite amount of time, foregoing the purpose according to math. For example, regarding the fundamental forces of nature, the current big bang theory suggests that none of the forces existed seperately at one point but were created by independently random particle interactions and other combinations; any other combinations of forces or their properties could have occurred as well, but it was random chance that this happened. People do not need to have a "reason" for existence except by that which they define themselves in their lifetimes.
Once we get into the realm of that which has no effect on our universe, just about anything can be said to exist and it cannot be proved to be right or wrong, which is why we should disregard it until all data on our universe has been collected and analyzed.
Also, if the beginning of the universe can be linked to the end, a loop will have been created and no further explanation would be necessary on that point, as we would have an transfinite number of universes in all of time, which is similarly transfinite in its length.
Why does it matter what you do while your alive if everything that you did immediately disapears once you die? You can't say that you have any impact on the "world". When you die, your own world is gone, in a way. According to your theory, it really doesn't matter whether you suffer your whole life or have a great time. And by considering life an "oppurtunity", you imply that it was given to you.
Your impact on the world lies in however you change it through the course of its history, which is determined by your influence on others and the use of technology to modify the universe. There is no "good" or "bad" impact here as far as the universe as a whole goes. Also, as Zylon said, life in the current sense could simply have been started off by an IRV and the chain of events continues to this day.