Bitcoin is both an oppurtunity and challenge depends on how an individual use it. One may call it as opportunity when he use it on his business. Bitcoin opens new opportunities because it is designed to allow financial transactions to take at a very low cost. One also may call it as a challenge, s/he may invest in a risky stock. We all know that bitcoin is very volatile in terms on its value.
Many questions in topic headlines here on forum lead's us to conclusion that everything depends from individual point of view. Like in most cases where bitcoin have dual role this case is the same, bitcoin is opportunity for people to earn something and in same time bitcoin is challenge for us, its testing our will for changing current economy system. Opportunity can be financial, we expect bitcoin price to grow, but people can earn from many other things, that is individual. But bitcoin has an opportunity to change the world, that is a big challenge for bitcoin and us. Social questions are important for healthy society, in many countries in the world people live without necessary things.
Look at the bitcoin as you wish, but bitcoin has a lot of side and big opportunity to do something good that can benefit to all the people. Idea is good, start is great we will see will it stay like that or people will manage to ruin one more good thing that could save us.