Note 7 at 1 Tim. 3:9: The "mystery of the faith" refers to the entire revelation from God, that is, the Holy Scriptures. The word mystery does not refer to something mysterious, but rather to something that not everyone understands. The scriptures state, "But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned" (1 Cor. 2:14). A deacon must be one who understands and applies the Word of God to his own life.

"Holding the mystery of the faith in a pure conscience" means there must not be an inconsistency between a deacon's profession of his beliefs, and his conduct. In other words, he must practice what he preaches; walk the walk and not just talk the talk. It's not enough for a deacon to believe the truth, he must live it. Our actions are a by-product of our beliefs (Jam. 2:18), therefore a deacon's actions must be appropriate as an indication that his beliefs are correct.