I think offerring courses in Arabic language for all regardless of age, gender, race should be enough. Whoever is interested should have access to this facility. People interested in finding the truth will first know what they have been taught was wrong somewhere. Only when have this passion inside, learning language for understanding the message would be helpful otherwise its just another language. Spreading of this message in all languages should continue as such so that those who have interest should know they have a way.
Regarding understanding this devine message, you can take a horse to a pond but you can't make him drink, always holds true.