It's not easy holding beliefs concerning sometimes outdated ideals, especially religion. There are so many different religions that it's hard to prove that one is more credible than another. Some are contradicting, while some are minor variations of others. There are theists, those who believe in a god or gods, as well as atheists, those who deny any gods. But while theism shows a strong benefit to the individual, atheism really doesn't have any significant benefits for the individual. Its real benefit is the lack of concern it has towards other beliefs. Unlike theism, it creates a more peaceful and less conflicting society. In theory, atheism is more beneficial to mankind as a whole.
These two groups, theists and atheists, are very different from each other. Theism relies on the need to prove itself right, and therefore in certain cases trying to prove other theories wrong. Some theists also feel it is their duty to spread their theology to other people in the world. Theism is such a wide and diverse group, however, which includes all religions and any other people that still believe in a higher power without committing to a religion. With so many different groups and ideas being spread around the world, theism in general is very opinionated, often times publicly expressed.
Atheism, on the other hand, is a very quiet and self-focused theory. It requires no spreading of ideas or really disproving others. Some individual atheists choose to get into the argument of proving their belief right while disproving other beliefs wrong, but that's only occasionally the case. Atheism is not just a belief in no god, but it can also be no belief in a god. In the latter case, there is no need for atheists to prove their theory right because there is no theory to prove.
It is easiest for a theist to prove their beliefs are the correct ones when the description of their god or gods and religion's background is unspecified, lacking strongly detailed information. The less there is to actually focus on, the easier it is to prove the theory. Theists must degrade the beliefs of others to make theirs true. This can be in the form of denying such things as evolution, homosexuality, and other forms of existence or lack there of after death. Some also believe that certain acts and beliefs that don't follow their own code of morals are universally immoral and therefore inappropriate for humankind.
On the other hand, atheists hardly have anything to prove. Atheism covers only two theories. The first is the belief that no god exists, and the second is no belief in a god or lack there of. They do not need to disprove the wide range of theories and beliefs that theism covers, though some choose to. An atheist can believe in many different ideologies in the world, including things like evolution, acceptance of homosexuality, and no afterlife, and still these things have no importance to atheism. They are individual concepts that can not conflict with the basic beliefs of atheism.
Second, theists tend to have this idea that they must make the world share their views on religion and life. For centuries, certain religious groups have felt obliged to spread their views over many foreign lands. Missionaries are common examples of this act, notable mostly in the Imperial Age. They have gone to great lengths to conquer the minds and rituals of others. In many cases these missionaries have suppressed groups of people, defining them as inferior thinking to the greater religious systems. Certain religious groups have even gone so far as to take over other groups' religious ceremonies, such as Christians turning pagan holidays into Christmas and Easer, in hopes of taking away their credibility. Even in this age some theists feel they must publicly humiliate atheists to get their point across. Former president George H.W. Bush was quoted as saying "No, I don't know that atheists should be considered as citizens, nor should they be considered patriots. This is one nation under God."
At times, conflict has arisen from the contact of two or more theist groups. In the mild situations, simple sharing of ideas and arguments of beliefs have taken place between the groups. However, in the most extreme, this conflict between the groups has caused major wars that devastate all mankind. The most powerful examples of this would be the Crusades, World War II, and the war between Israel and Palestine.
Contrary to this, atheists never create conflict within their group by sharing their beliefs. Since they all share the same essential belief to atheism, or have a lack of belief, then atheists have nothing to prove to each other. In this sense, they are all equal and have no need to create conflict. Any problems that come between them because of other views about life and society have nothing to do with atheism since they are not factors of being an atheist.
Finally, there are the different levels of gain for the individual in each belief. Most profitable is the spiritual enlightenment that theists receive. Through the discipline of their theology, theists are able to gain a form of holy wisdom that creates different views on how the world works, including theories and beliefs in the afterlife, the creation of life, and the purpose of mankind in the world. Many theist groups adopt the idea that it is their duty to help others, and that they must bring good into the world. This is beneficial to both the individual and the world.
The individual benefits of being an atheist are little, if any. There is no true measurable gain for not believing in a god. The choice of not believing in a god does not extend past that simple thought. Being an atheist does not prevent anyone from helping others or bettering society. Adaptation of different beliefs, including humanitarian morals, allows the atheist to participate in the same fields of beneficial work that theists do because of their religious principles. But in all fairness, theists too can adapt other beliefs that their religion does not cover, and therefore share this individual power with atheists.
Atheism and theism both have benefits and disadvantages for the individual and mankind as a whole. It truly comes down to the person's own choice. As is, there is no real tangible proof that either is right, nor will there probably ever be. Theism lies solely in faith while atheism simply denies such things.
The key factor here is both involve mankind. In theory, the best solution to the progress of mankind is to have one belief system. Many would suggest that one religion would suit this, but in reality it wouldn't. The fact that a religion is a following of people to a god defeats the purpose right there. The fundamental duty that an individual theist has to his/her god puts that god before any other human. This creates a society that honors a divine and abstract being before its own kind. When a god is placed higher in importance than humankind, it lowers the value of the society's ability to be united. That is why atheism is the more beneficial of the two. Theism puts the emphasis on the fact that a greater being controls the fate of man, while atheism shows that humankind itself is the only source to rely on for survival in life.