is it possible that we can use bitcoins in buying all commodities not only in one country but the entire wold? and how will this affect the economy.
Bitcoin as a world currency is not possible because some of the countries today are banning ico's and any source of cryptocurrency so if you want to earn bitcoins then migrate on the country where cryptocurrency is legalized on the area.
Bitcoin is strictly prohibited in some countries. But now bitcoin has a very strong Commodities so I remain optimistic that bitcoin can survive. Even in the future it is not impossible that bitcoin can be the world's currency used by all people in the world. Bitcoin like the dollar today, there are many places that receive payments via bitcoin and this is the view that bitcoin can be much better in the future.