Like numerous other verses, this short passage is oft-cited as evidence (by evangelicals, in particular) of the idea that individuals "accept" or must accept Christ as Lord. The emphasis is put on the cognitive assent to faith. The point is that Christ is not one's Lord (or anything else for that matter?) until they intellectually confess Christ as Lord. I've been uncomfortable with this idea for many years for many reasons. Intellectual acceptance of faith is important, no doubt. The question is whether intellectual assent to faith is merely evidence of faith or actually the activation of faith.
As usual, language matters. Actually, in this case, verbs matter. In this passage in Colossians two the verb is "you received" (obvious right?). Paul is referring to the Colossians as a whole, hence the second person plural formation. The issue with the reading of the verb here is that the emphasis is put the "you" rather than the "receive." There is an emphasis who received. The subject of the verb becomes more important than the action of the verb. When one moves the emphasis from "you" to "receive" the focus changes. The emphasis is now on the fact that someone from outside of oneself has been received. Sometimes this verse is translated "I take from." I would argue that the verb is more rightly translated "I receive from." In other words, whatever the Colossians ("you") comes from someone else; it's not something that they take, but something that that they get (perhaps like a gift?). Whatever the Colossians have, they have been gifted, not taken for themselves.
The Colossians are able to continue to live their lives in Christ because they have received Him. This is where the action changes. Once they have received Christ passively they start an active engagement with Christ based on their own actions. Christ has to be gifted for this personal and active "activity" to begin.
Evangelicals emphasis on action is correct, but it is misplaced. Christ is gifted. Our reaction to this giftedness is not a sign that we deserved the gift or went looking for it. Our reaction is what we do when we know we have the gift. The emphasis on action needs to be focused on our journey of discipleship. This is something we can all agree upon.