to be sufficient

I think the source of your confusion is that in English we can't say "be good to forgive people". We must say "be good *enough* to forgive people" for the sentence to make sense. A similar mistake that I hear from my students is "I'm lazy to recycle at home". The correct way to say this is "I'm *too* lazy to recycle at home". Maybe the logic is a little different in your native language, which is why the additional words feel unnecessary to you here. :)

be good ( to the best of your abilities )

no