Do we really need continuous integration if we skip all the tests before we click?

Each of our team members conducts all types of tests and ensures that they all pass before moving to the central repository. In this case, do we need a CI server? We have different development and production environments (mac vs linux). One simple reason, still, to have a CI server, if we set up the CI server on linux, is that we run the test in a more production environment. But are there good reasons to still have it?

thank