A lawyer said he can help w GC

I am only the temporarty GC holder, but my wife want to divorce. and I want to keep my green card, since I am not F1 student anymore. I turn to an American lawyer, he said that is nothing to hurt my status after my divorce as long as I can approve I was in marriage by good faith. and he can help me to keep my green card. How do you guys think the probability. and he told he even made one who was in marriage for only 6 months.
However, a lot of people here said it is very difficult for me to keep my GC. What should I do??