Is it worth applying for a job that could be a stretch for you, given your qualifications? How do you know if it's worth applying for a job when you are missing some of the requirements?
Some job postings you can read and immediately know that you are not qualified and would not be hired for the job. In general, if you read a posting and know you wouldn't be able to do the job, then you should not apply. However, there may be times when you come across a job that sounds great that you know you could do, but there are one or two things mentioned in the requirements that you don't have.
If the qualifications you are missing do not seem like they are major skills and essential in doing the job successfully, it could be worth applying.
Employers use their job advertisements as a way of listing everything their ideal candidate would have, but that doesn't mean they are going to find one person who has everything, and who seems like they will be a good fit for the job. If you can make a compelling case for yourself, and are positive that you are qualified and a good candidate; then find a way to get that across to the employer.
A cover letter and resume that grab an employer's attention by telling them all of the qualifications you DO have with examples that prove you can do the job are likely to get you to the next level in consideration for hiring. If a job is a stretch and you decide to apply, it's also important to identify any transferable skills you have that off balance a specific requirement you don't have. Related experience can be just as good: sometimes even better than one specific requirement.
Getting hired for a job takes more than just what you can put on paper. Your interview will reveal to an employer how you interact in person, and will give them an idea of how well you would fit into their company. If you make it to this level, then clearly the interviewer has decided you are capable of doing the job even if you are missing a requirement that they listed in the posting.
So think carefully about your personal value and take that leap of faith!