Usually people might express different combinations of emotions. Basically, emotions reflex people’s relation to life. Some people are chronically stuck in a negative emotion, like grief, while the others experience a positive one, like contentment. As a person gets aware to name his emotions, he might cope with the negative ones and replace them with positive.
Positive emotions such as joy, hope, optimism, love, contentment and gratitude promote an individual to a personal growth and improve the quality of one’s life and a sense of emotional well-being. The positive emotions entail creative thoughts which encourage people to explore the world. It has been shown that "individuals who express higher level of positive emotion show more constructive and flexible thinking".
Positive emotions give us energy. When one is excited and communicates with people he loves and enjoys, he sparkles with enthusiasm. Under these emotions people tend to think of more possibilities and options to solve any problem they face.
However, positive emotions are only one half of the equation. Negative emotions can cause a serious harm to any effect of positive emotions. While experiencing negative emotions a person might "miss the forest for the trees". Negative emotions are fueled by an underlying fear of the unknown.
However, if that becomes motivation to then learn it and deal with it that is very useful. The negative emotions such as fear or anger can motivate a person to take an immediate action against a threat or escape it.