Here Paul asks his readers to pray that he may fulfill his duty of making clear the meaning of the secret of Christ, the Christian message. The verb used here is the same as for “revealed” in 1.26. Paul must not only proclaim the message, but also “expound its deeper implications” (Beare).

The necessity implied in as I should (Good News Translation) or “as I ought” (Revised Standard Version) comes from God, who laid upon Paul the responsibility of proclaiming the gospel. A literal rendering of that I may speak, as I should, might suggest merely that Paul is asking the Colossian Christians to pray for him to be able to speak clearly or to enunciate well the message. What Paul is praying for is the ability to proclaim the message in such a way as to make it clear, and it is this proclamation of the message which is his obligation. Therefore, it may be more appropriate to render verse 4 as “therefore pray that I may announce this message in such a way as to make it clear, for that is what I must do.”

Quoted with permission from Bratcher, Robert G. and Nida, Eugene A. A Handbook on Paul’s Letter to the Colossians. (UBS Handbook Series). New York: UBS, 1977. For this and other handbooks for translators see here .