A problem is a negative occurence that needs to be solved.
A problem is seen to be bad because it is something that we do not want.
A challenge may be either a positive or a negative situation, depending on whether we succeed in the challenge or not.
A challenge may be viewed as good or bad depending on whether the outcome is a success or a failure. It is not the challenge that is good or bad but our perspective of the outcome.
An opportunity is a positive experience that we accept without hesitation.
An opportunity is good because it will give us what we think or know that we want.
A situation, an occurence and an experience are all the same thing. However how we perceive them is always down to our own unique, individual and exclusive perspective of Life.
Whether Life is a challenge, a problem, or an opportunity is just a matter of personal choice.
Whether we see Life as a challenge, a problem or an opportunity is indicative of our Emotional Energy.