There they can hear and learn of Jesus Christ. Have desire for them to be saved. Pray for them. Invite them to a place or an event where they will hear gospel. For whosoever shall call upon the name of the Lord shall be saved.
Mass conversions are very rare.
Even with Jesus, they came by ones and twos. B. Growth comes from personal contact. Few are saved from telecasts or radio broadcasts. Most who are saved in church services are there because they were invited by a friend or neighbor. C. Personal work has no substitute.