Every project should have a persona to make sure you will create a projection of what type of users will use your design, and what steps you will create to assure that these type of personas will be the right fit to your project.
Why is important?
Personas help them see multiple sides of the user base and make more informed decisions as a team. The best way for them do this is to listen to as many users as possible, as quickly as possible. The users know best, and working their feedback into your UX should be a very important part of your design. Also, Personas are fictional characters, which you create based upon your research in order to represent the different user types that might use your service, product, site, or brand in a similar way.
Research is important?
Every project is different, and you cannot start a UX project without having a research since you can missed a lot of good resources that you can use for your project.