I think that the concept of an afterlife would have some type of impact on human behavior. If an individual is concerned of their own condition in the afterlife, it might play a large role in how they behave in this life. For example, if someone is concerned with redemption in the afterlife being dependent on how they act in this one, their actions might be in line with what the expectation for behavior should be. Yet, by the same token, if individuals were not concerned with the presence of the afterlife or some type of judgment outside of it, they might not find a need to moderate their actions. In the end, the impact of the afterlife on human behavior is dependent on how strongly individuals accept its premise. It is also dependent on how much individuals wish to embrace its influence on this life. It in this capacity where the role and function of the afterlife holds an impact on whether or not one acts accordingly. This makes the prospect of an afterlife something that is nearly impossible to determine without understanding where an individual stands on the issue of the afterlife.
As different cultures have different views of the afterlife, the impact on behavior varies. Several ancient cultures believed that the dead could take with them what they had owned/earned in life, leading to the likes of the "Terracotta Army" statues, which were enclosed by the hundreds in the gravesite of China's first emperor. The statues were meant as a representation of the emperor's actual army, and were believed to protect him in the afterlife. For the Norse, those who fell in battle were rewarded with a heavenly paradise where drinks never run dry. Early Judaic belief indicated that everyone went to the same place, regardless of their actions in life.
Most of the modern-day religions utilize the concepts of heaven and hell, which provide an implication that good deeds will ultimately be rewarded and bad deeds severely punished. The emphasis, however, is often placed on how gastly are the punishments for evil - as a means of scaring people into acting morally upright. Hell is frequently described as having several layers, and punishments to match all manner of wrongdoing, whereas heaven is simply a place of happiness and harmony. For those who can be frightened into behaving in a socially acceptable manner, the heaven/hell mentality will likely ensure they lead a wholesome life. Of course, historically this also led to problems - such as in the Middle Ages, when clergymen actually sold "get into heaven free" cards, which supposedly would enable the buyer to go to heaven regardless of their actions on earth.
At the other end of the scale, you have people who don't believe in any sort of afterlife. The most radical of these, acting under the assumption that this life is all they get, are likely to do whatever they want so as not to feel regret later. Cultures which believe in an afterlife are often prone to worry more about what happens after death, rather than what is happening now. Those with no belief in an afterlife tend to focus solely on the present.
In 'Srimadbhagawat', a scripture for the Hindus, there are so many example of consequences and results on afterlife. Also, there is a theory named 'Janmantarbad rahasya' in which stated about the consequences of behavior of this life. So if somebody is really an atheist and listen to them and act accordingly, certainly there would come a great difference in his behavior in this life. If we affect vices of others and act accordingly for the suffering of other people we will have the consequences. Therefore, I believe it makes a difference.
In all religions it is told that greedyness is a sin. To have control over it we need to obey the teaching of the scriptures and my case it has worked nicely. I was a bad guy and since I began listening to the lessons of bhagawat, I feel I have shade away so many of my bad habits by imitating the followers and by chanting verses from Srimadbhagawatgita and Srimadbhagawat.
Is the prospect of an after life comforting or challenging?