Whereby (pros ho). “Looking to which,” “according to which.”
When ye read (anaginōskontes). This Epistle will be read in public.
My understanding in the mystery of Christ (tēn sunesin mou en tōi mustēriōi tou Christou). My “comprehension” (sunesin, Col 1:9; Col 2:2). Every sermon reveals the preacher’s grasp of “the mystery of Christ.” If he has no insight into Christ, he has no call to preach.