1 Timothy 3:10

3:10 And these also must be tested first and then let them serve as deacons if they are found blameless.

1 Timothy 3:13

3:13 For those who have served well as deacons gain a good standing for themselves ¹  and great boldness in the faith that is in Christ Jesus. ² 

[3:13]  ¹ sn The statement those who have served well as deacons gain a good standing for themselves is reminiscent of Jesus’ teaching (Matt 20:26-28; Mark 10:43-45) that the one who wishes to be great must be a servant (διάκονος [diakonos], used here of deacons) of all, just as the Son of Man came not to be served but to serve (διακονέω [diakonew], as in 1 Tim 3:10, 13).

[3:13]  ² sn In the phrase the faith that is in Christ Jesus, the term faith seems to mean “what Christians believe, Christian truth,” rather than personal trust in Christ. So the whole phrase could mean that others will come to place greater confidence in them regarding Christian truth; but the word “confidence” is much more likely to refer to their own boldness to act on the truth of their convictions.