If you can invest big amount to buy some btc then i guess you can earn huge profiit in near future! because btc price is upper!
Gambling is one of thr thing i know that you can able to get 1 bitcoin or much higher income in a month. But it is too much risky than trading, gambling is for people who have lot of capital but if your capital is few i thing you must go on trading without requiring minimum investment.
In a month? Not really, you can get that income from gambling in a minute. You can also lost a lot, it's not recommended to gamble if you need money because you will probably lose money.
Gambling is not really a way to earn.
Gambling is good to have fun sometimes and we cannot rely on it for making money or for living and if you are depending only on gambling then you are putting your life at huge risk and not only you but even your family will suffer from this decision so its better to find other slow and steady methods of earning bitcoins.