1.verbTo advertise one’s religious beliefs; to convert (someone) to one’s own faith or religious movement or encourage them to do so.
"It is illegal to proselytize [children] in some countries"
2.verb(by extension) To advertise a non-religious belief, way of living, cause, point of view, (scientific) hypothesis, social or other position, political party, or other organization; to convince someone to join such a cause or organization or support such a position; to recruit someone.
"He has the annoying habit of proselytizing [his political views] at parties."