Estoy bien y haciendo el bien.
estoy bien. I am good
Estoy bien = I'm OK/doing fine etc.
Fine can be synonymous with good. this words mean "bien" or "bueno"
Just fine thank you!! ^^ And hello to you too!
Doing good = haciendo bueno but this sounds terrible in Spanish. Generally speaking you should say "doing well" which is haciendo bien.
Tiempos buenos
good ones
Well, if you were asked first, you can reply with "bueno, gracias, y tu?"
El está haciendo bien
like you are fine, healthy, ok. get the picture?
Fine means good so they are telling you that you are doing a good job and you should keep it up, unless they say it in a sarcastic voice then it means the opposite.
Im doing pretty good here