Charles Ellicott Commentary Colossians 2:7

"rooted and builded up in him, and established in your faith, even as ye were taught, abounding in thanksgiving." — Colossians 2:7 (ASV)

Rooted and built up in him.—There is a significant change of tense in the original, having been rooted—i.e. , rooted and grounded in Him once for all, and being built up continually on that Foundation. (Compare to 1 Corinthians 3:9–15). St. Paul urges them to seek not only the first basis of their faith, but also their continual growth, in Christ alone, by continual “strengthening in the faith” which rests in Him. We may remember that in Gnostic teaching, faith was considered good for the beginner or the common herd; “knowledge” was the bright particular jewel of those who advanced to perfection.

Abounding (or, overflowing) therein with thanksgiving.—The metaphor is changed. The cup of faith, filled to the full, runs over in that thanksgiving which is the expression both of faith and love.