Apparently, Hebrew Amen ("so be it") and Maltese emmen ("to believe") are related, both going back to the root 'mn meaning (in Hebrew, according to Wikipedia): to be firm, confirmed, reliable, faithful, have faith, believe.
(And Mammon may also be related, possibly from *ma'mon =? "security, deposit.)
Emmen is an interesting word in Maltese because it's one of the very few verbs of Semitic origin beginning with a vowel. (I'm not sure how many there are, but ISTR reading that there were only a handful.)