There can be only one purpose for a Church, to follow the marching orders of her Lord:

"Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son and of the Holy Ghost: teaching them to observe all things whatsoever I have commanded you." - Matthew 28:19-20

• "Go" We are to be going, active, not sitting still
• "Teach" [matheteuo] To instruct
• "All nations" [ethnos] Without ethnic distinction
• 'Baptizing" [baptizo] To immerse, dip or submerge in water
• "Them" All who believe
• "In the name of" [onoma] By the authority of
• "The Father, Son, Holy Ghost," The One true God manifested in the tri-unity of His sacred Persons
• "Teaching"[didasko] Indoctrinating, teaching doctrine
• "Them to observe" [tereo] To carefully watch and hold fast
• "All things whatsoever I have commanded you." All the will of Christ as revealed in the holy Scriptures.