No, you have to do some effort as well.
Guru can definitely relieve you of your sins. When you commit a sin and you realize that you made a mistake, you cannot relieve yourself of sin, but the Guru can definitely do it for you. So in that sense, yes!
At the same time, you have to do Purusharth (self-effort). You need to do some good work. And the sense of love and devotion is equally proportionate to the amount of karma that gets released.