They joined and went to Morek, a theocracy of SA. They asked for a estate, and were told by either the lord or the message group of lords that you must join the church to have in estate in Morek, a theocracy.
It is an IG requirement to be a member of SA to get an estate in Caiyun. The Lord of Caiyun may or may not make it sound as if that was a requirement in all regions of Morek, depending on the forum in which this requirement is aired.