Muhyiddin, when asked to comment on Paulsen's remarks against Jakim on Twitter, said Paulsen's action must be dealt with appropriately.
"The relevant authorities should investigate Paulsen's statement and appropriate action be taken as many non-Muslims do not understand what Islam really is.
"Islam is not an extremist religion, (and) since when have our people (Malaysians) acted extraordinarily? Islam is the most moderate religion," he said.
Muhyiddin was speaking at a news conference after viewing the situation on the first day of the 2015 school session at SK Cyberjaya and SM Cyberjaya, here.
He said the allegation of Friday sermons being deviated should not come about at all as the sermons do not ony revolve around the Islamic way of life but also societal and humanity issues.
"Perhaps Paulsen does not know this at all or has not learned about Islam," he said.
Paulsen had made the statement accusing Jakim of spreading extremism every Friday (through the sermons) on his Twitter page on Jan 9.