What makes something a religious issue (a religion only issue) or a government issue is whether or not there is a human victim.
- If there is no human victim, it is a matter for religion to address (or not), not government.
- If there is a human victim, then the matter is proper for secular law (and religion) to address.
Application of the power of government (force of law against individuals) should require that a victim be identified first. Otherwise, the secular authorities could address any issue like religions can...and our free society would be destroyed.
Religion should use only persuasion to change behavior, and so can address all issues.
Governments can use force to change behavior, and so the issues governments can address should be limited, and that limit is usually to consequential laws (to protect victims). Only in totalitarian states are governments allowed to address non-consequential issues, like matters of sharia law.