Col. 2.6 (NKJV) As you therefore have received Christ Jesus the Lord, so walk in Him, (2 step process – receive & walk)

Col. 2.7 (NKJV) rooted and built up in Him and established in the faith, as you have been taught, abounding in it with thanksgiving.

Overflowing means super abounding, abounding richly in that which ought never to be absent from any of our devotions; namely, the grateful acknowledgment to God that they had been made acquainted with truths so precious and glorious respecting .