John Gills Exposition of the Bible Commentary

Verse 8 (Colossians 1:8)

Who also declared unto us your love in the Spirit. Not only their love to God, and Christ, and to all the saints, which is before mentioned, but their love to the apostle; though they had only heard of him, and of his great capacity for, and faithfulness and usefulness in preaching of the Gospel, which had greatly endeared him to them. This, he says, was in the Spirit; it was spiritual love, to distinguish it from a carnal and worldly one; they loved him for the spiritual grace that was in him, the spiritual gifts bestowed on him, the spiritual service he was engaged in, and the spiritual usefulness he was of: or they loved him in, and with their spirits, with all their hearts, sincerely, and without dissimulation; and though they had never seen him in the flesh, yet being, as it were, present with him in spirit, their affections were knit unto him: or this their love was "in the Holy Spirit", as the Ethiopic version reads it; it was a fruit of the Spirit of God, which he had implanted in their hearts in regeneration, as is also love to God, and likewise to Christ.

- John Gills Exposition of the Bible Commentary