Apostasy laws deterred Christian missionary work in Islamic lands.

Evidence

Organized missionary activity is distinctively Christian, and from early times Christian missions were active on and beyond the frontiers of Christendom. For centuries this activity did not include the lands of Islam, for a very good reason: apostasy in Muslim law is a capital offence, involving the execution both of the apostate and of his seducer. This did rather put a damper on Christian missionary activities among Muslims. — Bernard Lewis, From Babel to Dragomans, 735

Categorization

• corroborated: 2 independent passages support this claim — Bernard Lewis, From Babel to Dragomans: Interpreting…, 735
• XREF: connects to: A Christian courtier’s voluntary circumcision was read as apostasy’s threshold