The first part of this verse literally reads: “O the depth of the riches and wisdom and knowledge of God” (Revised Standard Version). This is in the form of an exclamation, but a literal rendering such as this is archaic. It is more natural to begin an exclamation with “how” (see also Jerusalem Bible). When this change is made, the word “depth” must be rendered by deep. But if one says “How deep are God’s riches,” then it may be assumed by the reader that this is something one must dig for. So the Good News Translation translates “depth” by great in the first exclamation and introduces deep in the second, since deep in conjunction with wisdom and knowledge occasions no difficulty for the English reader.

In some languages, however, one cannot translate how great are God’s riches, since this would simply imply that God is very wealthy. Even in the form of a strong affirmation, “God has great riches,” the reference might be merely to his considerable wealth and not to “the riches of his grace,” which is the usual manner in which Paul speaks of God’s “riches.” Accordingly, the first exclamation must be translated in some languages as “God is indeed very good to all” or “God does indeed show great mercy (or grace).” Similarly, in many languages one cannot speak of wisdom or knowledge as being “deep.” In fact, one must say “God is indeed very wise and has much knowledge.”

The two questions, Who can explain his decisions? Who can understand his ways? are also exclamations in Greek. It is possible to retain the form of exclamation (for example, “No one can explain his decisions! No one can understand his ways!”), but the question form is more natural in an English construction of this type. In some languages strong affirmations may be more satisfactory—for example, “no one can explain his decisions; no one can understand his ways.”

The words translated explain and understand are actually verbal adjectives in Greek. The first of these terms describes something that cannot be found by searching for it, while the other suggests footprints that cannot be tracked down. Explain his decisions may perhaps be best translated as “explain how he decides.” Understand his ways may be rendered as “understand why he does what he does.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on Paul’s Letter to the Romans. (UBS Handbook Series). New York: UBS, 1973. For this and other handbooks for translators see here .