“for many of us.” The Hebrew is more literally, “we have sinned greatly in this matter,” but reading the English that way makes it seem like the problem that will take so long is the terrible nature of the sin, but that is not the case. The problem would take a long time and the sin was “great” because such a great number of people were involved in the sin and it was difficult and would have to be dealt with on almost a case-by-case basis. The best answer to make the English read clearly is to nuance the English to make the text clear, and many English versions do that.