The absolutes of the religion, the matters over which there are no permissible differences of opinion, are very few; and there are even fewer in legislative matters relating to the public sphere. The bulk of what we know as Islamic Law is Fiqh, and the issues about which there is unanimous consensus are fewer than the issues about which there are divergent opinions. In matters where permissible differences exist, you cannot impose your own view upon others. You can debate, and discuss, and try to convince them, and they can do the same with you; but ultimately, you must respect each other’s right to disagree, uphold brotherhood, and move on.
There are issues that have been debated among scholars for centuries. So be aware that these differences are never going to be resolved; because they are not supposed to be. This is from the leniency of the Deen. Islamism must embrace this principle; indeed, we all must.
If we do not, Political Islam will fail as a project, because it will accomplish nothing but conflict between groups with varying interpretations of the Shari’ah; and it will tear us apart as a community.