As different scholars and Ayatollahs have different Fatwas on certain issues, how will Allah judge between the Muslims acting upon the different rulings?
Bismillah
Thank you for your question. The need to follow the fatwa of a jurist stems from the requirement to act on knowledge. In a world of imperfect knowledge it is natural that different experts will come to different conclusions. For the person acting on rulings their responsibility is to try their best to act on knowledge by acting in correspondence with the conclusions of those they believe are in a better position to ascertain what their stance should be on a particular issue and that is what they will be judged on. And Allah is the All Knowing.
May you always be successful