I was trying to figure out what the reason was. The previous sentence said, “You learned the gospel from Epaphras, our dear fellow slave – a faithful minister of Christ on our behalf – who also told us of your love in the Spirit” But why would their live in the Spirit be the reason for him to pray for them? I would have thought it was more reason to give thanks.
Later, after more discussion with Thomas Kuruvilla, I am now thinking that the reason is that they learned the gospel from Epaphras and Paul found out about it.
Colossians 1:21-22 says “And you were at one time strangers and enemies in your minds as expressed through your evil deeds, but now he has reconciled you by his physical body through death to present you holy, without blemish, and blameless before him”
We used to be God's enemies, but because of Jesus, that is no longer the case😄
Colossians 1:25-27 says, “I became a servant of the church according to the stewardship from God – given to me for you – in order to complete the word of God, that is, the mystery that has been kept hidden from ages and generations, but has now been revealed to his saints. God wanted to make known to them the glorious riches of this mystery among the Gentiles, which is Christ in you, the hope of glory.” God used to be hidden only among the Israelites, but now is revealed to all people.