Alas, religious people always want an exception to secular rule of law and in some countries in the West managed to carve out exceptions

https://www.gov.uk/government/publications/applying-sharia-l...

Secular law allows it's citizens discretions for settling family disputes and inheritance. Religious people often use that discretion to use religious rules from their religion. Nonreligious people benefit from the same discretion. This is not an exception from secular law, all secular laws continue to apply.

There should be a principle that secular law of the country overrides religious laws if the outcome is less favourable for the affected.

"A secular state need not suppress Islam"

What about a secular state that doesn't want to become an Islamic state, but has a significant minority that has the opposite wish?

AFAIK this is the most important common political problem across the Islamic world. Many organizations such as the Muslim Brotherhood want to Islamize their respective secular countries, some by peaceful means, others by violence. There has already been at least a dozen civil wars around that issue.

A liberal secular state must respect the will of its citizenry, whatever it is. It must also suppress violent sedition with violence. Expressing that responsibility as suppressing religion per se is counterproductive

> A liberal secular state must respect the will of its citizenry, whatever it is

No. A tolerant, secular, liberal state should not respect the will of its people if the will of (the majority of) its people is to become an intolerant, religious, oppressive state. It is OK -- possibly even necessary -- to have a set of core founding principals which must never be abandoned.

If you're saying that core founding principles were so important then you must feel that slavery shouldn't have been abolished, no?

Slavery was a “state rights” issue from the beginning. In what way was it part of the core founding principles of the US?

Also having “core founding principles” doesn’t mean that they are valid or that you got them right from the beginning.

> liberal secular state must respect the will of its citizenry, whatever it is

This is majoritarianism. Not liberalism, and certainly not democracy.

So democratically abolishing democracy?

> respect the will of its citizenry, whatever it is

How do you define that? Is it always what the majority decides? What if the liberal secular government knows that going along with the will of the people will result in a minority of the population losing most of their rights and potentially suffering extreme oppression?

One could could assume that after learning what happened in Germany in the 30s (and some other comparable situations) most people would agree that even liberal states need to draw a line at some point.

Not really? Islamists in secular Muslim states are trying to overturn the secular legal all the time (and have succeeded on numerous occasions). Often they end up compromising and end up with a mixed system which is also far from ideal.