In vv. 15-20 Paul goes into great depth describing who the "Son of His Love" (cf. v. 13) actually is. This is one of the most extended and exalted portraits of who Christ is and what he has accomplished that Paul has painted for us in all his writings. In vv. 15 and 17 Paul highlights Christ's preeminence over all creation as the unique image bearer of God the Father. Paul's reasoning for this is found in v. 16 and in vv. 19-20 where he asserts that all things have been created in him and through him and for him and that through his incarnation and through the cross all things are reconciled to the Father.
ὅς ἐστιν εἰκὼν τοῦ θεοῦ τοῦ ἀοράτου, πρωτότοκος πάσης κτίσεως,
He is the image of the invisible God, the firstborn of all creation.
ὅτι ἐν αὐτῷ ἐκτίσθη τὰ πάντα
For [in reference to, in terms of, in the sphere of] him all things were created,
ἐν τοῖς οὐρανοῖς καὶ ἐπὶ τῆς γῆς, τὰ ὁρατὰ καὶ τὰ ἀόρατα,
(when I say all things, I am including all things) in heaven and on earth, visible and invisible,
εἴτε θρόνοι εἴτε κυριότητες εἴτε ἀρχαὶ εἴτε ἐξουσίαι•
(by invisible I am including) whether thrones or dominions or rulers or authorities—
τὰ πάντα διʼ αὐτοῦ
( furthermore ,) all things were created through him
καὶ εἰς αὐτὸν ἔκτισται•
and (climactically, all things were created) for him.
καὶ αὐτός ἐστιν πρὸ πάντων
( therefore ) he is before all things,
καὶ τὰ πάντα ἐν αὐτῷ συνέστηκεν,
and in him all things hold together.
καὶ αὐτός ἐστιν ἡ κεφαλὴ τοῦ σώματος τῆς ἐκκλησίας•
And he is the head of the body, the church.
ὅς ἐστιν ἀρχή, πρωτότοκος ἐκ τῶν νεκρῶν,
He is the beginning, the firstborn from the dead,
ἵνα γένηται ἐν πᾶσιν αὐτὸς πρωτεύων,
that in everything he might be preeminent.
ὅτι ἐν αὐτῷ εὐδόκησεν πᾶν τὸ πλήρωμα κατοικῆσαι
For in him all the fullness of God was pleased to dwell,
καὶ διʼ αὐτοῦ ἀποκαταλλάξαι τὰ πάντα εἰς αὐτόν,
and through him (God was pleased) to reconcile to him (i.e. Christ) all things,
εἰρηνοποιήσας διὰ τοῦ αἵματος τοῦ σταυροῦ αὐτοῦ,
( in that God is) making peace by the blood of his cross,
[διʼ αὐτοῦ] εἴτε τὰ ἐπὶ τῆς γῆς εἴτε τὰ ἐν τοῖς οὐρανοῖς.
(let me say it more specifically , God was pleased to reconcile all things) whether on earth or in heaven.