Church activities do not predict or drive long-term spiritual growth. More precisely, increasing church attendance and participation in organized ministry activities do not predict or drive spiritual growth for people who are in the more advanced stages of spiritual development. Church activities have the greatest influence in the early stages of spiritual growth, but things like personal spiritual practices, including prayer and Bible reading, have far more influence later in the spiritual journey.
Hawkins, Greg L. (2011). Move: What 1,000 Churches Reveal about Spiritual Growth (Kindle Locations 219-222). Zondervan. Kindle Edition.