You [Gentiles] also, who are in Christ, after having heard the message of truth, the good news about your salvation, and [after] believing in Him, were sealed [i.e., as evidence of ownership] with the promised Holy Spirit. [or, "the Holy Spirit who brings promises"].

so that He could dedicate her [to Himself], after cleansing her by means of the washing of water [i.e., immersion], accompanied by the word. [Note: "The word" here refers either to a person's profession of faith (See Rom. 10:9) or to the Gospel message (See Rom. 10:17), both of which are associated with immersion].

Therefore, put on the full armor of God, so that you can withstand [the devil, See verse 11] when the evil day comes. And, after you have done everything you can, still remain standing firm [in the faith].