The Dative in Colossians 1:16

Greek: ὅτι ἐν αὐτῷ ἐκτίσθη τὰ πάντα ἐν τοῖς οὐρανοῖς καὶ ἐπὶ τῆς γῆς, τὰ ὁρατὰ καὶ τὰ ἀόρατα, εἴτε θρόνοι εἴτε κυριότητες εἴτε ἀρχαὶ εἴτε ἐξουσίαι· τὰ πάντα δι' αὐτοῦ καὶ εἰς αὐτὸν ἔκτισται·

I think it would be fair to say that ἐν + the dative case here could be rendered "in him." As for the dative case itself, I originally learned that it describes how action affects the indirect object: I equally learned that casus dativus/ἡ δοτικὴ πτῶσις is the "to" or "for" case. But while these observations are technically correct, the matter becomes more complex with Greek prepositions and cases.

For instance, context is a factor that one must consider when translating the dative case. Additionally, one must reflect on the usus loquendi of the particular dative being analyzed. What is its particular usage within a determinate context?

For example, ἐν + dative could be locative (maybe locative of sphere) or it could be instrumental. The Old Vine's Dictionary used to describe constructions like Colossians 1:16 that way. Compare 2 Cor. 5:19.

Nevertheless, I prefer to say that Colossians 1:16 is probably a dative of agent while I acknowledge that it could be understood differently. Cf. also Heb. 1:1-3.