lay missionary
A Christian layperson who engages in evangelistic work without being ordained clergy.
He works in the community as a lay missionary.
伝道者 is a broader term for any evangelist or missionary, while 信徒伝動者 specifically refers to a layperson (not ordained).
Compound of 信徒 (believer, layperson) and 伝動者 (evangelist, missionary). The exact historical derivation is uncertain; the spelling is conventionally associated with Christian lay missionary work.