The distinction between secularism and Islam is a false one. The Ottoman khilafa decriminalized homosexuality in 1858. It gave apostates the freedom to leave Islam. It allowed equal rights to non-Muslims. And it abolished slavery. Long before many Western nations did. Scholars said that Allah's shariah is secularism. Wahabbis have done a good job of rewriting history to make it appear as though these are Western concepts, but what do you expect from those cockroaches.
There's a place in Islam for ijtihad, and the Tanzimat reforms were a part of this process. From Wikipedia:
The reforms sought to emancipate the empire's non-Muslim subjects and more thoroughly integrate non-Turks into Ottoman society by enhancing their civil liberties and granting them equality throughout the empire.
Many changes were made to improve civil liberties, but many Muslims saw them as foreign influence on the world of Islam. That perception complicated reformist efforts made by the state.
https://en.m.wikipedia.org/wiki/Tanzimat
It's a mistake to let Saudi vermin have a monopoly on sacred terms like Shariah. The Ottomans killed Wahabbi heretics with abandon. Numerous wars were fought to exterminate them. Islamic leaders considered them satanic evildoers. Their leader Ibn Taymiyyah spent most of his life in jail. He was not under any illusion what scholars thought of his kafir ideology. It was not until Lawrence of Arabia instigated the Arabs against the Ottoman caliphate and supplied them with arms that these people got the secular boot off their neck. It's time to return that boot where it belongs.
Allah supports freedom. If he didn't, the Shaytan would not he allowed to mislead people for thousands of years.
Allah gave him freedom of speech and freedom of action before the First Amendment was ever conceived. If Allah permits someone whose stated ambition is to lie and to deceive, then how much more tolerant would he be of someone who sincerely and genuinely believes that his non-Islamic beliefs are true? The Quran is clear on this point: there is no compulsion in religion. Libertarianism is compatible with the Quran and Sunnah.
The work of sheikh Khalid Abu Fadl is a good resource for those who want to dig deeper.