Just recently, Google announces via Google Webmaster Central Blog that beginning in May they will roll out an update to better improve the mobile search results putting in effect that being a Google passed mobile-friendly site is very important as a ranking signal in this update.
Last year we were informed by Google that our websites should be already mobile ready (responsive) and mobile-friendly, if you are still not sure about this, here are some guides you can use
Google still reiterates that the intent of the search query is “still a very strong signal”, and even when a page does not passed mobile-friendly test and though content is identified as relevant, it could still very well get rankings “if it is great”.
Meaning that, you need to update your website and make it mobile responsive and mobile-friendly. There is still a lot of time to prepare and update your website.