There is nothing that would benefit society more than the complete abandonment of religious belief in favor of a purely atheistic society. A society where everyone is atheist would be truly the epitome of scientific and intellectual development, productivity, and the highest standard of living.
Studies consistently show that nations with higher rates of atheism/secularism tend to have lower crime rates, higher productivity, lower rates of divorce and lower birth rates. These are all good things. Further, statistics repeatedly show that people who are not religious are much more likely to hold graduate and/or terminal degrees (especially in mathematics, the sciences, and related disciplines) than their religious counterparts.
A purely atheistic society would not be disrupted by religious fundamentalists, nor would it be hindered by dangerous religious beliefs that compromise the safety of the general public. Such a society would not be hindered by dangerous beliefs such as creationism, and would allow for the most dramatic scientific advancements known to man. It would be all-around better.
I really wish that it was feasible to start another society. We'd be a society of all atheists, and anyone found to be practicing religion would not be jailed or killed, but rather simply deported. Further, anyone who wasn't certified an atheist would not be allowed to enter into our society, and our focus would be on education and academic research, population control, and productivity. We'd have the highest standard of living index, and the lowest crime rate.
A purely atheistic society benefits all involved. Why don't we move that way? The answer is simple: because of a lack of education and the myths of religion still permeate society. The benefits of a purely atheistic society are well-known and well-documented, and society would be smart to move into this direction.