There is not doubt that Thessolonica was a growing church. Paul describes them - "your work produced by faith, your labor prompted by love, and your endurance inspired by hope" (I Thessalonians 1:3)
That level of solid Christian growth is built on a foundation of faith, love and hope, and thrives in an atmosphere that is conducive to maturity.
Atmosphere has a lot to do with growth - lush vegetation flourishes in a tropical rain forest but does not do well in the frigid Antarctica.
The "Antarctica" kind of climate that stifles growth is: guilt, criticism, fear, intimidation, power plays, politics, individualism, "hot house" (protected and will not make it through the storms), "bonsai" (miniature of the real thing because its roots are constantly clipped by legalism), and the "potted plant" (keeps on moving to the best speaker or the best concert but has no deep roots in the soil of the Community where it is located).
Paul says that the climate that produced growth at Thessolonica was "Grace," "Peace," and "Thanksgiving." I Thessalonians 1:1,2)
If you are breathing "Antarctic" air, build a foundation of hope, love, and faith, and encourage your Community to breathe an atmosphere of Grace, Peace, and Thanksgiving. That lavish atmosphere will help you and others grow to your fullest potential in Christ.
Praising God for that kind of Community ~ Bob