Advantages of secularism

Freedom to choose and practice your belief/faith/religion.

No state laws could be made against religious system.

Political systems can make and enforce civil codes without any influence of religious code.

Freedom to respectfully leave the state, upon disagreement.

Common good of the people is way better than any political compulsion.

Explanation:

It is a political principle applicable to states: a secular state may be supported by religious believers and be the home of widespread religious belief. Indeed, secularism is the best guarantee of freedom of religion or belief - but the enemy of religious privilege.