and has made known to us your love in the Spirit.
Colossians 1:8 (ESV)
What does 'love in the Spirit' means in Colossians 1:8?
To the Colossians, the apostle Paul and Timothy (cp. Col. 1:1) wrote that Epaphras (cp. Col. 1:7) "declared to us your love in the Spirit" (Col. 1:8). It is this same "love" that the apostle Paul refers to in Col. 1:4, when he writes,
after we heard of your faith in Christ Jesus and [your] love that is for all the saints.
ἀκούσαντες τὴν πίστιν ὑμῶν ἐν Χριστῷ Ἰησοῦ καὶ τὴν ἀγάπην τὴν εἰς πάντας τοὺς ἁγίους TR, 1550
The apostle Paul describes the love as "in the Spirit" (ἐν πνεύματι) because (Rom. 5:5):
...God's love is poured out in our hearts by the Holy Spirit which is given to us.
...ἡ ἀγάπη τοῦ θεοῦ ἐκκέχυται ἐν ταῖς καρδίαις ἡμῶν διὰ πνεύματος ἁγίου τοῦ δοθέντος ἡμῖν TR, 1550