Getting a job is a matter of course for most adults. However, if you have the option not to get a job because your partner is the primary breadwinner or because you are independently wealthy, you might need particular reasons to become employed. Likewise, if you are a teen or college student, you can assess the benefits of working to decide whether it is something you'd like to engage in.
A primary benefit of working is the income it provides. If you are dependent on your partner for money, you might wish to have a part-time job to provide your own reserves of cash. If you're a student, you might want to reduce your dependence on loans by getting a job that can give you some pay for rent and other expenses.
In particular if you are a young worker, a job can provide valuable experience and help you build your resume. Even if your work is only tangentially related to your ultimate career goals -- for example, working in a pet store while you study to become a vet -- in a competitive job market every little bit helps. If you are an older worker who has suffered a recent layoff and is looking to change industries, a job can help you gain experience in a new field that you have just begun to explore.
As much as getting a job helps you gain experience in your chosen field, it can also help you to find out what you don't like. An entry-level job in your dream career could be illuminating enough for you to decide you do not enjoy working in that particular field. Finding that out early, through job experience and before you've spent dollars and time on education, can be a benefit to you.
Working outside of the home usually means working with people. Especially if you are on the hunt for a long-term or permanent job, getting to know people in your chosen industry is invaluable. Getting a temporary position while you're still searching gives you contacts who can help you find jobs that are not advertised; they can also serve as references later in your career.
Self-Respect and Positive Example
A job gives you a positive sense of self-worth in that you are contributing to society. Income you garner from working will have an extra value to you because of the work you put in to earn it. If you are raising children, your choice to work can set a positive example for them. Working also helps you feel better about yourself and more connected to your community.