Religious believers often claim that life is given meaning and a sense of fulfillment when they surrender themselves to God, and also that this life is more meaningful if there is an afterlife to look forward to. They argue that life is pointless without such beliefs, and ask why an atheist should bother at all if it is all just going to end anyway.
Religious people often worry that life may be meaningless and imagine that it can only be redeemed by the promise of eternal happiness beyond the grave. They worry that atheists do not have this solace to fall back on. Atheists, on the other hand, tend to be quite sure that this life is precious and should be lived to the full.
The fact that some of the most high-achieving individuals in history - from Einstein to Freud to Marx to Orwell - did not need a belief in God to live lives of great direction, purpose and significance should be evidence enough of this.
Belief in a creator-god does not automatically provide life with a meaning. If a person says that religion invests their life with purpose and meaning, then they are either admitting that they are content to have serving God as the meaning of their life (what Nietsche called “slave morality”), or they are assuming and trusting that God has some genuine worthwhile purpose for them but that they may not find that purpose out until some hypothetical after-life. To an atheist it is more important to find what makes this life precious and worth living, rather than hoping that the “next one” will be better.
There is no reason to believe that life needs to be eternal in order to be meaningful. Indeed, there is evidence that quite the opposite in the case: for example, a film, a perfomance, a novel or a sporting event without end would completely lose any meaning. In the same way, we can question what would be the point of doing anything at all if we had an eternity to live, with nothing to bring it into focus and give it some urgency and poignancy.
From a purely biological perspective, the purpose of life appears to be survival and reproduction. However, most people, atheist or otherwise, would probably agree that the purpose and meaning of life needs to be more than just this, and also more than the short-term achievement of goals or the pursuit of transitory pleasure. However, what does constitute satisfaction or contentment can vary considerably from person to person. For some, a hedonistic life does provide ongoing (and not just transitory) pleasure. For others, a quiet, slow labour of love can provide deep and long-lasting satisfaction.
Having said all that, many atheists think that the question “what is the meaning of life?” is just as silly as asking “what is the meaning of a cup of coffee”, and do not believe that life has any meaning or purpose, nor that it requires one: it simply is. The Scopes Monkey Trial lawyer Clarence Darrow once said: “The purpose of life is living. Men and women should get the most they can out of their lives."
COUNTER ARGUMENTS ARE WELCOMED.. just be rational when making your point.