As long as there are arms in the world, each of us should have the right to have our own for our personal protection. Just like the nations have nuclear weapons to keep others from using their nukes, we should have arms to dissuade people form using their arms on us.
I do not believe that it is good for every human to be able to carry a gun. Not everyone is mentally fit to understand the consequences of using a weapon. I don't think it should be impossible to get a license to own a weapon, but there are ways to make that more difficult. I think this would greatly cut down the violence in our nation.
One, there is the obvious issue of age. Children (who are humans) should not be allowed to bear arms. But, this is a moot point to the issue of those that are mentally unstable or ill. These individuals that cannot recognize the consequences of their actions should not be allowed to own a gun. They are dangerous since they are not rational and the laws that regulate the rest of us do not work to quell their actions.
I fully support the right to bear arms. However, there are some people who should not have them, such as those with serious mental illnesses and those with a history of violent crimes. Anyone who wishes to own weapons should be required to be tested to ensure they can safely own said weapons.