Col 2:7 Having been rooted and being built up in Him [Christ] ... Eph 3:17 That Christ may make His home in your hearts through faith, that you, being rooted and grounded in love. 4:16 Out from whom [Christ] all the Body...causes the growth of the Body unto the building up of itself in love.
To be rooted in Him is for the growth in life. In this verse [Col 2:7] Paul views the believers as plants who have been rooted in Christ as the soil. However, many Christians have not been rooted in Christ adequately.
If we have been rooted in Christ properly, there will be no need to talk much about the ground of the church. The ground of the church is oneness. But the base of this oneness is the one Spirit, the one Lord, and the one God and Father, as mentioned by Paul in Ephesians 4.
If we have been truly rooted in Christ, in our experience He will be the base of our oneness. Having been rooted in Christ, we now are “being built up in Him” (2:7). To be built up is for the building of the Body.
Although we have been rooted, we are still in the process of being built up. This is a corporate matter as well as a personal matter. A building is not composed merely of one item, but of many items that have been fitted together.
We need to be rooted in Christ and also built up in the church. In order to be built up corporately, the Colossians had to forsake the Judaistic observances and the heathen ordinances and philosophies. Otherwise, they would have been transplanted from Christ and rooted in something else.
Furthermore, they would have been led astray from the church life. Whenever we take in some kind of philosophy, ordinance, observance, or practice in place of Christ, the church life is annulled. We are divided from those believers who have different opinions concerning these matters.
Those who are preoccupied with such things will eventually cease to care about the church life.