Christ Jesus' Words describe a healing church: "Where two or three are gathered together in my name, there am I in the midst of them." Matt. 18:20 As a thimble of water or a bucket contains the same elements, so a small or large church can have the same God-given, healing ingredients.
What are these ingredients? Praise, spirituality, love, are primary. Whether the worshipers are few or many, the reverent worship of God, "in spirit and in truth," See John 4:24 heals.