Do You Believe in Your Own Abilities?
"I could never do that-I'm just not good enough!"
"I can't cope with that kind of stress...I'm not going to try at all."
"If I try that, I'll just make a fool of myself."
We've all experienced the encouragement that having others believe in us can provide. However, something that is rarely acknowledged is our level of belief in ourselves. What happens if we lack belief in our own abilities, and what are the benefits of enhancing this belief?
Self-efficacy is one's belief in their ability to perform the behaviours necessary to complete a specific task or goal.  As part of Albert Bandura's Social Cognitive Theory (SCT), self-efficacy is a key source of motivation to engage and persist in behaviours. Before we attempt a goal, we first have to believe that the actions we are engaging in will lead to the accomplishment of our goal. This is referred to as an "outcome expectancy": your estimate that a particular action will result in a specific outcome.  With this estimate in place, you then consider whether your attempt at the given action will be sufficient to achieve the desired outcome. This is called an "efficacy expectancy." To understand the difference between the two, consider the following scenario:
Let's say you want to hit a home run. You do a bit of research, and find there are two factors (in a simplified example) that determine the outcome of your attempt:
1. Exit speed-the speed at which the ball leaves your bat
2. Launch angle
With a bit of basic physics and the dimensions of your stadium, you could come up with multiple combinations of these two factors that would result in a home run. So now we know what to do to hit a home run, but I definitely don't think that I can do it (baseball has never been my strong point!) So for me, I have the right outcome expectancy to hit a home run, but my efficacy expectancy will likely prevent me from ever attempting to do so myself (which in this case, is likely a good thing...)
The problem with having a lack of self-efficacy is when it prevents us from attempting tasks for which we have (or could develop) the skills to accomplish. How strongly you believe in your abilities affects your likelihood of attempting related tasks.  Self-efficacy's impact also goes beyond behaviour initiation and affects our persistence and continued effort in a task. Those who have higher self-efficacy will more actively persist in the face of challenges or setbacks. In doing so, these individuals often experience success or positive experiences that reinforce their sense of efficacy. 
A study from the University of California examined the impact of emotional self-efficacy on anxiety-related impairments on math performance in elementary school students. Previous studies have established a link between anxiety and impaired academic performance.  However, not all students with anxiety experience a reduction in academic abilities. What is the difference between students who fulfill their potential and those who are hampered by their anxiety? The factors contributing to academic success are widespread and complex, but in the context of this study, the level of protective factors a student possesses impacts the negative consequences of anxiety they experience.  Cognitive resources such as the ability to focus and access one's memories may become more available when you down-regulate excessive anxiety. Therefore, the ability to down-regulate emotions could be considered a protective factor against anxiety.  Emotional self-efficacy is one's perceived ability to regulate negative emotions when faced with stress. What the study found is that high levels of self-efficacy protected students from anxiety-related impairments in math. Additionally, only students with low self-efficacy had test performances that could be negatively predicted by high levels of anxiety. 
I think it is clear the importance of self-efficacy to one's ability to face and overcome challenges. The next important question is, "How does one increase self-efficacy?"
Self-efficacy has 4 sources: 
Mastery Experiences: success boosts self-efficacy and failure degrades it
Vicarious Experience: observing others succeed, especially when those individuals are similar to oneself
Verbal Persuasion: credible motivation feedback and guidance
Emotional State: positive mood
By engaging in tasks of moderate difficulty, we can both be challenged and experience success, therefore boosting self-efficacy. The use of small, short-term goals in building up to a long-term goal can provide motivation and confidence along the way to accomplishing something challenging. Finally, receiving feedback that accurately portrays a situation, but attributes it accurately to the correct cause (e.g. You failed this test, not because you are a failure, but rather because you didn't read the instructions) helps us understand why we fail at times, and how we can maintain and increase our ability at accomplishing a given task.
 Bandura, A. (1977). Self-efficacy: toward a unifying theory of behavioral
change.Psychological review,84(2), 191.
 Galla, B. M., & Wood, J. J. (2012). Emotional self-efficacy moderates anxiety-related
impairments in math performance in elementary school-age youth.Personality and
Individual Differences,52(2), 118-122.
 Kaplan, S. (2016, July 11). The physics behind hitting a home run. Retrieved from
Kirk , K. (2020, April 3). Self-Efficacy: Helping Students Believe in Themselves. Retrieved
Tsang, S. K., Hui, E. K., & Law, B. (2012). Self-efficacy as a positive youth development
construct: a conceptual review.The Scientific World Journal,2012.