The end in Paul’s request as a minister of Christ for the prayers of believers

‘That I may open my mouth boldly, to make known the mystery of the gospel.’      The third branch in the division of the words presents us with the end why he desires their prayers for utterance to be granted him, expressed in these words—‘that I may open my mouth boldly, to make known the mystery of the gospel;’ where there are these three observables.  First. The sublime nature of the gospel—it is ‘a mystery.’  Second. Wherein lies the work of a gospel minister—‘to make known the mystery of the gospel.’  Third. The manner how he is to perform this work —‘that I may open my mouth boldly.’

What is meant by a ‘mystery,’ and in what respects the gospel is one.

           First Observable.  The sublime nature of the gospel—it is ‘a mystery.’  The Greek word µLFJZD­4T< some derive from µLXT, to teach any secret be­longing to religion; others of µbT or µb.T, to shut the mouth, because those that were initiated or admitted to be present at the religious rites and mysteries of the heathens—who were called µbFJ"4 —might not reveal them to those that were •µb<J@4, or not initiated.  Therefore they had an image before the temple, holding his finger upon his mouth, to put them in mind as they went in and out of keeping secret what was done within.  Indeed the mysteries in their idolatrous worship were so impure and filthy that nothing but secrecy could keep them from being abhorred and detested by the more sober part of mankind; and it is not unworthy of our noting what I find observed to my hand by a learned pen—that the Spirit of God should make choice of that word in the New Testament so often to express the holy doctrine of truth and salvation contained in it, which was so vilely abused by those heathenish idolaters; surely it shows them to be over‑scrupulous that judge it unlawful any way to make use of those names or things which have been abused by heathens or idolaters.  (R. Sanderson on I Tim. 3:16.)  But, to return to the word ‘mystery;’ it hath obtained in our usual speech to be applied to any secret, natural, civil, or religious, which lies out of the road of vulgar under­standings.  In Scripture it is generally used for reli­gious secrets; and it is taken both in an evil sense and in a good.