As nouns the difference between deacon and clerk
is that
deacon is (church history) a designated minister of charity in the early church (see acts 6:1-6) while
clerk is one who occupationally works with records, accounts, letters, etc; an office worker.
As verbs the difference between deacon and clerk
is that
deacon is (christianity|music) for a choir leader to lead a hymn by speaking one or two lines at a time, which are then sung by the choir while
clerk is to act as a clerk, to perform the duties or functions of a clerk.