A.T. Robertson Commentary Colossians 3:17

"And whatsoever ye do, in word or in deed, [do] all in the name of the Lord Jesus, giving thanks to God the Father through him." — Colossians 3:17 (ASV)

Whatsoever ye do (παν οτ εαν ποιητε). Indefinite relative (everything whatever) with εαν and the present active subjunctive, a common idiom in such clauses.

Do all (παντα). The imperative ποιειτε has to be supplied from ποιητε in the relative clause. Παντα is repeated from παν (singular), but in the plural (all things). Παν is left as a nominative absolute as in Mt 10:32; Luke 12:10. This is a sort of Golden Rule for Christians "in the name of the Lord Jesus" (εν ονοματ Κυριου Ιησου), in the spirit of the Lord Jesus (Ephesians 5:20). What follows (directions to the various groups) is in this same vein. Sociological problems have always existed. Paul puts his finger on the sore spot in each group with unerring skill like a true diagnostician.