I read the following in a daily devotion that I get from www.austin-sparks.net.
The higher position of “Ephesians” is this – that now, being quickened and raised together with Christ and seated in the heavenlies is a matter of relatedness to other believers, and in that relatedness, you are going to find your fullness. You are never going to find spiritual enlargement just as an isolated, separate individual, but in relation with other believers. (T. Austin Sparks, A Way of Growth)
Ephesians states very clearly that the way to grow into the fullness of Christ’s stature is together. We grow as we speak the truth in love to one another, and we grow as "every part does its share" (4:16).
This is a teaching that most people do not know about. Who teaches that we cannot grow without one another?
The answer is almost no one. We need to share it because it’s taught not just in Ephesians 4, but rather thoroughly in 1 Corinthians 12 as well.