The Greek word for continuing earnestly means “to be courageously persistent” or “to hold fast and not let go” and refers here to persistent prayer (Acts 1:14; Romans 12:12; Ephesians 6:18; 1 Thessalonians 5:17). Being vigilant in its most general sense means to stay awake while praying. But Paul has in mind the broader implication of staying alert for specific needs about which to pray, rather than being vague and unfocused.
Commentary from the MacArthur study Bible, notes for Colossians 4:2.
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