Examples...

Older men are to be temperate, dignified, sensible, sound in faith, in love, in perseverance. ~ Titus 2:2 (NASB) 

Sound Judgment

For through the grace given to me I say to everyone among you not to think more highly of himself than he ought to think; but to think so as to have sound judgment, as God has allotted to each a measure of faith. ~ Romans 12:3 (NASB)

Sound in the Faith

“Older men are to be sober-minded, dignified, self-controlled, sound in faith, in love, and in steadfastness.” ~ Titus 2:2 (ESV)