A world religion that forcibly prevents a person from embracing another religion and compels a person to remain in a religion unwillingly is inconsistent. When Christians punished apostates and heretics, as they did for much of Christianity’s history, the Christian faith itself was divided. When Muslims insist, as many still do, that “once a person accepts Islam out of his free will he is not allowed to leave it,” Islam, too, at is at odds with itself.
If religion is to be embraced freely, that free choice must obtain throughout the religious life of a person, not just at its beginning.

Miroslav Volf, Flourishing : Why we need religion in a globalized world