2nd Amendment gives militia right to bear arms, not individuals

[Sinixstar]

I'm sorry, I was wrong it was not article 4, it is found in article 1, section 10 and reads as follows

"No State shall, without the Consent of Congress, lay any Duty of Tonnage, keep Troops, or Ships of War in time of Peace, enter into any Agreement or Compact with another State, or with a foreign Power, or engage in War, unless actually invaded, or in such imminent Danger as will not admit of delay."

To me if the second amendment was to grant a state to keep a militia then how can they keep troops?

Because a militia is not a standing army of troops. They're not professional regular army. They're average every day citizens, who as citizens are expected to stand up on behalf of their country and other citizens in a time of crisis.

The idea is that while there is an inalienable god-given right bestowed upon all men, all men must also live up to a certain responsibility, morality, and sense of civic duty. God gave you the right to bear arms, because god also made you a man - and as a man you should have the spine to step up and do what's right. (ie - are able bodied and of sound mind and character)
This is why the power of government is granted by the willingness of the governed, as those "governed" are the ones who are viewed as being the responsible "brother's keeper"s of society. You don't need the standing army, because in a time of crisis - it is expected that "the militia" will rise to meet it's civic duty. make sense?

The "militia" is a collective body - yes, but you cannot have a collective body without the individual. It is only when those individuals are called upon to act that they come together as a collective body. Without the individual right, no collective right is possible. Especially when you look at it in the context I outlined above.