The second admendment specifcally states that the People's right to keep and bear arms shall not be infringed. It might just say that so as to keep the government from deciding who is good and who is bad, because the government might abuse this power and apply it unlawfully. @Camul
You dont have to own guns to benefit from the government not having control of them. First, if the government has the ability to redact admendments at will than what stops the redactment of say the first, third, fourth, etc.(atm they need a two thrids majority and approval from the president)? Second, the government would have the ability to abuse its people if the people's only means for fending off the governemnts abuse is a little knife.
People being able to use guns to defend themselves helps everyone, especially the weak and helpless(old ladies and young women come to mind) because they would not have the physical strength to fend off an attacker. Guns are the great equalizer, whether with the people and government or victims of abusers.