Gradually and Tactfully convert the people.

...the upper classes ... need the right type of people to approach them, and a method that can suit their mentality. Our teaching methods should allow a certain degree of elasticity in establishing contacts with various types of individual seekers. Every inquirer has to be approached from his own angle. Those who are essentially of the mystic type should first be given those teachings of the Cause which emphasize the nature and value of spiritual realities; while those who are practically minded and of a positive type are naturally more ready and inclined to accept the social aspect of the Teachings. But of course, gradually the entire Message, in all its aspects and with the full implications it entails, should be explained to the newcomer. For to be a believer means to accept the Cause in its wholeness, and not to adhere to some of its teachings.

However, as already stated, this ought to be done gradually and tactfully. For conversion is after all a slow process.

(From a letter dated 28 December 1936 written on behalf of Shoghi Effendi to an individual believer)