To manifest something is to concentrate one’s understanding in order to accomplish or acquire something. This is why manifestation can be good and bad.

Advantages:

Positive Thinking: It inculcates positive thinking in a person and therefore it has an indirect effect on the mental health and perspective of the individual.
Goal Setting: It is also capable of providing a better understanding about goal setting and actualization.
Call To Actions: Manifesting one’s vision can be of great importance in getting people to work towards their objectives.

Disadvantages:

Oversimplification: Manifestation may simplify the nature of the problem limiting the understanding of how complicated some issues can be resulting into false hope and later frustration.
-Little effort: It might lack the motivation of the individual to strive toward an end but merely think it should happen.
-Toxic Positivity: Encouraging the extreme form of positive thinking may cause ignoring of constructive and necessary negative feelings ay the same time leaving intact the persons problem.
Conclusion:

Therefore, manifestation is an effective technique provided there is a balance between work, and the positive and negative aspects of life.