After time will tendonitis come back?!

I have had tendonitis in my rotar cuff for over a year. I eventually did some physical therapy for a couple months and then I got a shot of cortizone in it about 4 months ago. After that it felt a lot better and I finally started working out again but it was still limiting me some. So I just got another shot this past Tuesday. One of my teachers told me that it'd come back. If I go back to working out in a couple weeks and I work out for the rest of this year, will that cause me to have more inflammation or cause my tendonitis to return and flare back up? PLEASE HELP