I agree that one should not quit, but I also have to disagree with that.
Firstly, I would never had come accross a business opportunity that was exactly right for me had I not quit the many opportunities I have tried before. Yet again, I think I needed those experiences to open my eyes to what a real business really is. I needed to know it when I found it.
Then, I know many people that started the same business as me, but was not successful until 8 months or more of trying to build their business, but when they succeeded, they succeeded.
I think the reason why most people quit, is because of their mindset. When people do not have the mindset to make a success, they will not and they blame it on the opportunity. It is hard to change your mindset, it is a gradual process and if you don't work on it, you will not be as successful as you can be.
I believe that in order not to quit something, you need to believe in it. Those people who stuck it out for 8 months or longer, believed in what they were doing. It will be difficult to try make a success of something you do not believe in. And If you don't believe in it, your mindset will not be right.
That is exactly why I knew I found the right opportunity for me. I believed in it, and this company helped me to develop myself in such a way as to be successful in all aspects of my life. I believed in the opportunity and I will never quit, because of that.