Bitcoin has a great potential yes and it is also a nice asset that one should invest on but saying that if someone invest in long term that they will have profit and it is 100% sure is what an investor is not suppose to tell someone especially a newbie because we don't know what tomorrow holds for Bitcoin, as a matter of fact no investment that it profit or return in long term is 100% sure or guarantee perhaps we should put away the thoughts of Bitcoin profit being 100% in a long period of time, remember what we are using to invest is what we can afford to let go so telling someone for sure may look like misleading the person, that is making the person to invest more than they are suppose to... because of the assurance you gave them.
You are still not understanding the concept of investing in long term. Every Bitcoin investor that invested for long term has made profits and can boost of a successful investment. Over the years, Bitcoin has not failed any long-term investor. If you choose to invest now and hold for 5 to 10 years i am assuring you that you will be profiting from your investment, then. So, i don't see any reason why an investor cannot tell another investor with certainty to invest for long term.
I understand the fact that no investment is guaranteed. However long-term investment is different. If an investor properly stays committed to their Bitcoin investment and reach their investment goal for long term that investment will be successful.
When someone understands how to invest on Bitcoin for long-term, the person will not bother to listen to people who doesn't understand the reason why experienced investors like to invest for long-term, it's obvious that many people will not believe that the price of Bitcoin is getting increased at any time and also decreasing at any time, but who those who knows the future of Bitcoin they're the one
that deliberately invest and hold for long-term, that's it's been encouraged not to use the little you have to invest on Bitcoin, if you want make a profit in cryptocurrency investment especially in bitcoins investment, try to use what you can afford to lose and invest and also use your spare money to invest on Bitcoin.