What I do is, I just dont care.
Just forgive them. Just pretend nothing happend(happens when you really forgive him/here)
If I see this gossiper, gossiping about someon else. I always make jokes that it doesn't make sense doing it and stuff.(dont force it, or be focused doing this, just be on the mentality of not caring, and having really the mindley-mentality of not liking gossip)
And o yea, be subtle. Dont be like: In the bible they say if may not gossip, you maybe go to hell!
But be like: O noo your gossiping again(humoristic way), I dont think that guy/girl is not wierd. I think she/he is okay, why do you think that way?
Ofcourse you need to feel that way about here/he. But a good christian love everybody as there neighbour
But because of this, usually they also stop gossiping about you.
Why? because they know your a good girl/guy, and they will feel bad gossiping about you.