1 Timothy 3:9

“Holding the mystery of the faith, etc.] The doctrine of the Gospel, called the “faith”, because it contains things to be believed; proposes Christ the object of faith; is the means by which faith comes, and is unprofitable without it: it is called “the mystery”, because it is of divine revelation, and could have never been discovered by human reason; and now it is revealed, the modus of many things contained in it remains a mystery; several of the doctrines of it are mysterious ones, particularly the doctrine of the Trinity; and which the ancient Jews call by this very name, f49 atwnmyhmd azr, “the mystery of faith”; the incarnation of the Son of God, the union of the saints to Christ, and…”

“the mystery of the faith--holding the faith, which to the natural man remains a mystery, but which has been revealed by the Spirit to them (Rom 16:25; Co1 2:7-10), in a pure conscience (Ti1 1:5, Ti1 1:19). ("Pure," that is, in which nothing base or foreign is intermixed [TITTMANN]). Though deacons were not ordinarily called on to preach (Stephen and Philip are not exceptions to this, since it was as evangelists, rather than as deacons, they preached), yet as being office-bearers in the Church, and having much intercourse with all the members, they especially needed to have this characteristic, which every Christian ought to have.”

“Holding the mystery of the faith - On the word “mystery,” see notes on 1 Corinthians 2:7. It means that which had been concealed, or hidden, but which was now revealed. The word “faith” here, is synonymous with “the gospel;” and the sense is, that he should hold firmly the great doctrines of the Christian religion which had been so long concealed from people, but which were now revealed. The reason is obvious. Though not a preacher, yet his influence and example would be great, and a man who held material error ought not to be in office. In a pure conscience - A mere orthodox faith was not all that was necessary, for it was possible that a man might be professedly firm in the belief of the…”

“Holding fast the faith in a pure conscience - Steadfast in faith, holy in heart and life. 1 Timothy 3:10”

“Holding: Ti1 1:5, Ti1 1:19 the mystery: Ti1 3:16; Jo2 1:9, Jo2 1:10 1 Timothy 3:10”