4:2-6 No duties can be done aright, unless we persevere in fervent prayer, and watch therein with thanksgiving. The people are to pray particularly for their ministers. Believers are exhorted to right conduct towards unbelievers. Be careful in all converse with them, to do them good, and recommend religion by all fit means. Diligence in redeeming time, commends religion to the good opinion of others. Even what is only carelessness may cause a lasting prejudice against the truth. Let all discourse be discreet and seasonable, as becomes Christians. Though it be not always of grace, it must always be with grace. Though our discourse be of that which is common, yet it must be in a Christian manner. Grace is the salt which seasons our discourse, and keeps it from corrupting. It is not enough to answer what is asked, unless we answer aright also.
3. for us—myself and Timothy (Col 1:1).
a door of utterance—Translate, "a door for the word." Not as in Eph 6:19, where power of "utterance" is his petition. Here it is an opportunity for preaching the word, which would be best afforded by his release from prison (1Co 16:9; 2Co 2:12; Phm 22; Re 3:8).
to speak—so that we may speak.
the mystery of Christ—(Col 1:27).
for which … also—on account of which I am (not only "an ambassador," Eph 6:20, but) ALSO in bonds.