The word translated charged
(μαρτυρόμενοι/marturomenoi) has the sense of insisting.
1 Paul was not apologetic about the requirements and demands of the Christian life; in addition to comforting the new believers with regard to their persecution, he also showed them that the gospel placed certain non-negotiable demands on followers of Jesus. This urgency is also reflected in Paul’s practice some years later in Ephesus, where he never stopped warning each of you night and day with tears
(Acts 20:31).
12 we exhorted each one of you and encouraged you and charged you to walk in a manner worthy of God, who calls you into his own kingdom and glory.