Nowadays its so hard to get 1BTC of Bitcoin. I think the most possible way to earn 1BTC is by freelancing, if you know how to make websites, do graphic designs. This is possible.
This is what I keep on saying especially with those people like OP that doesn't want to invest. Because this amount is truly hard to get if you don't have something to offer or to sell. But if you can do a business like buying and selling of the things that you've got. Probably you can earn this amount if you can have good volume of sales.
Yes you cannot earn 1btc or 2 in a month by not doing much. you have to make sure you learn more about btc, once you have good idea about idea then try to trade which is risky but at the same time possibilities are you will earn more. otherwise if you are skilled at animation or gaming or web designing then you can do some freelance project which will give you the best in return.
Trading isn't enough if you are not willing to invest some capital on it or you don't have a bigger capital. I prefer the web designing and other programming skills because they are in demand. But animation is also good, the best way on earning is none other than being employed.
my way of thinking is like this, you don't have to set the limit. Because when we set the limit either we become anxious or annoyed. first you need to consider bitcoin as money, the more you work hard, show your skillset, learn and explore the more you earn. same applies here too. you must have good knowledge of btc, join the singed campaign, invest in btc now try to buy more coins and sell after some days that itself a best way to get the profit from btc.
But I think OP is interested in knowing how he can earn 1 btc in a month or two so putting fiat money in buying it is not applicable here as if you have money then you can even buy more then 1 btc in a month and that is not a big deal and when we talk only about earning 1 btc in a month then its not at all easy as you need to have multiple skills and not only skills will help you but you should also have good multiple projects in your hands from where you can expect some income in bitcoins.