The word “prudence” is fading from the English language. It’s being replaced by other words. Normally, this kind of thing is fine. Words fall out of usage all the time.
But biblically, in terms of translating from Greek to English, “prudence” does its job so well that we may not want to part with it—at least not until we have found the perfect replacement.
To show you what I mean, let me ask you to read Ephesians 1:7-8 in the King James Version. Note the word “prudence” at the end:
In whom we have redemption through his blood, the forgiveness of sins, according to the riches of his grace; Wherein he hath abounded toward us in all wisdom and prudence…
Many translations say “wisdom and understanding” instead of “wisdom in prudence.” (NIV, ISV, NLT)
Others say “wisdom and insight.” (ESV, NASB)
The New King James Version keeps “prudence,” but adds “understanding” in a footnote, anticipating that readers won’t know what the first word means.
The Amplified Bible says, “wisdom and understanding [with practical insight].”
So what do we lose when we repalce the word “prudence”? The Amplified Bible demonstrates it by adding the word “practical.”
Insight could be purely theoretical, so it must be qualified here as practical. But you would never have to say “practical prudence,” because practicality is built into what the word means.
Wisdom, understanding, and insight are all great words and great gifts from God. But none of these words necessarily describe behavior.
Prudence does. Prudence is wisdom, understanding, and insight put into practice in complex yet down-to-earth situations.
The Merriam-Webster Dictionary gives “prudence” four definitions. In doing so, it uses phrases like, “ability to govern and discipline oneself,” “the management of affairs,” and “the use of resources.” All very practical language.
In this respect, “prudence” gets us pretty close to the meaning of the Greek word Paul used in Ephesians 1:8 and elsewhere.
Stephen Fowl pointed this out in his commentary on Ephesians:
The word ‘prudence’ here may sound old-fashioned to contemporary readers. Both the RSV and the NRSV translate the Greek word φρόνησις with ‘insight.’ I think there are a couple of reasons to prefer ‘prudence.’ The Greek word φρόνησις was used widely in classical moral philosophy to refer to practical wisdom, the ability to know how to apply general moral rules to specific situations in the right ways. This requires both insight and a variety of habits that are born of practice. Paul clearly uses φρόνησις in just this way throughout Philippians, where the vast majority of his uses of this term occur. Hence φρόνησις means insight but also includes practice in life. When Christian theologians writing in Latin encounter φρόνησις, they translate the term with ‘prudentia.‘ Thus prudence, while old-fashioned, may give readers pause to recall that Paul is not simply speaking of disembodied insight, but also of a way of life.
 Fowl, Stephen E., Ephesians: A Commentary (2012, Westminster John Knox Press)