In his book, The Religious Test, Damon Linker describes what he calls The Liberal Bargain. It works like this. In America, we are given a constitutional right for Freedom of Religion. In order to have this freedom, no religion can exert control over others. The moment one religion decides to use the legal process to exert control over others, is the moment we lose freedom of religion.
This bargain is the act of believers giving up their “ambition to political rule in the name of their faith” in exchange for the freedom to worship God however they wish, without state interference.
He also makes this perceptive remark:
What if a faith forbids its adherents to accept the liberal bargain? What if it explicitly refuses to permit believers to decouple their political and religious convictions? What if it demands unity–unity in the name of one set of non-negotiable theological truths? Such a religion may be incompatible with liberalism. Whether Islam is inherently illiberal in precisely this way is one of the most pressing questions confronting the Western world today.
Something we should all think about–Christians included.