Paul is seeking to remind the Colossian believers (and in turn, us) that before they had received Christ as their Lord and Savior, they were also “sons of disobedience.” It can become so easy for us who have been believers for a period of time to “forget” that we also were just as the pagans around us. In fact, many of the Colossian believers practiced these very acts listed in the previous verses. There are a number of locations in the New Testament where, after listing the catalog of sins, the reader is reminded that they were also marked by these very things prior to their conversion.
Many of Paul’s critics in his day found him foolish in espousing gospel liberty for all in the church. They felt that this liberty might be okay for those of Jewish background, having been trained in the law of God, but for those who came straight out of a pagan background, they felt that a probationary period should be in place before their acceptance into the church.
Paul on the other hand, had a different policy in respect to this idea. He believed that although they had been pagans, they now were in Christ and Christ was in them. If they looked to themselves as dead to the former way of life, then the Christ-life would manifest itself in them and they would mature, just as the Colossian believers had been doing.
The Greek word pote translated here as once literally means “once upon a time,” or “formerly.” And the word translated “walked” (Greek peripateo) is used figuratively here to encompass the whole round of activities in an individual's life, whether they are unconverted or believers. This was the way that they had lived (Greek zao) prior to their conversion and indwelling of Christ. It was also a reminder to them that their life should also show a difference from those around them. They were to no longer live as the pagans around them lived, nor should they accept the ways of the pagan world as being acceptable.
Prayer: Father, let me never forget from where I have come, as i muse upon how great my salvation is, I realize how much it cost You and Your Son. I must remember where I have come from to be able to encourage and help those who are new to walking in Your way. Help me to be a help to those who are growing in Your Truth and Way. Amen.
 Refer to Rom. 6:19-21; 1 Cor. 6:9-11; Tit. 3:3; and 1 Pet. 4:1-5 for other examples of this.
 Bruce. (1984) Page 145.
 Perschbacher. (1990) Page 330.
 Vine. (1996) Page 664.