Epaphras who is one of you (Epaphrās ho ex humōn). See note on Col 1:7 for previous mention of this brother who had brought Paul news from Colossae.
Always striving for you (pantote agōnizomenos huper hēmōn). See note on Col 1:29 of Paul.
That ye may stand (hina stathēte). Final clause, first aorist passive subjunctive (according to Aleph B) rather than the usual second aorist active subjunctives (stēte) of histēmi (according to A C D).
Fully assured (peplērophorēmenoi). Perfect passive participle of plērophoreō, late compound, for which see note on Luk 1:1; Rom 14:5.