Colossians 4:2

προσκαρτερεῖτε : cf. Romans 12:12; Acts 1:14. Steadfastness in prayer is opposed to “fainting” in it, the best illustration being the importunate widow and the importunate friend. γρηγοροῦντες may mean that they are to watch against growing weary so that the prayer becomes mechanical, or, as Soden takes it, against confused thought. But perhaps it is not so much alertness in prayer that is meant as the watchfulness which manifests itself in the form of prayer (so Hofm., Haupt). In favour of this is the use of γρηγ. in the religious sense for watchfulness against temptation. ἐν εὐχαριστίᾳ : thanksgiving is added, because it springs from the heart thankful for God's gifts, and therefore watchful against losing them.