Harmony of the Old and New Testaments
26 I will briefly set forth the manner of life according to these virtues, one by one, after I have brought forward, as I promised, passages from the Old Testament parallel to those I have been quoting from the New Testament. For is Paul alone in saying that we should be joined to God so that there should be nothing between to separate us? Does not the prophet say the same most aptly and concisely in the words, "It is good for me to cleave to God?" Does not this one word cleave express all that the apostle says at length about love? And do not the words, It is good, point to the apostle's statement, "All things issue in good to them that love God?" Thus in one clause and in two words the prophet sets forth the power and the fruit of love.
27. And as the apostle says that the Son of God is the virtue of God and the wisdom of God—virtue being understood to refer to action, and wisdom to teaching (as in the gospel these two things are expressed in the words, "All things were made by Him," which belongs to action and virtue; and then, referring to teaching and the knowledge of the truth, he says, "The life was the light of men")—could anything agree better with these passages than what is said in the Old Testament of wisdom, "She reaches from end to end in strength, and orders all things sweetly?" For reaching in strength expresses virtue, while ordering sweetly expresses skill and method. But if this seems obscure, see what follows: "And of all," he says, "God loved her; for she teaches the knowledge of God, and chooses His works." Nothing more is found here about action; for choosing works is not the same as working, so this refers to teaching. There remains action to correspond with the virtue, to complete the truth we wish to prove. Read then what comes next: "But if," he says, "the possession which is desired in life is honorable, what is more honorable than wisdom, which works all things?" Could anything be brought forward more striking or more distinct than this, or even more fully expressed? Or, if you wish more, hear another passage of the same meaning. "Wisdom," he says, "teaches sobriety, and justice, and virtue." Sobriety refers, I think, to the knowledge of the truth, or to teaching; justice and virtue to work and action. And I know nothing comparable to these two things, that is, to efficiency in action and sobriety in contemplation, which the virtue of God and the wisdom of God, that is, the Son of God, gives to them that love Him, when the same prophet goes on to show their value; for it is thus stated: "Wisdom teaches sobriety, and justice, and virtue, than which nothing is more useful in life to man."
28. Perhaps some may think that those passages do not refer to the Son of God. What, then, is taught in the following words: "She displays the nobility of her birth, having her dwelling with God?" To what does birth refer but to parentage? And does not dwelling with the Father claim and assert equality? Again, as Paul says that the Son of God is the wisdom of God, and as the Lord Himself says, "No man knows the Father save the only-begotten Son," what could be more concordant than those words of the prophet: "With You is wisdom which knows Your works, which was present at the time of Your making the world, and knew what would be pleasing in Your eyes?" And as Christ is called the truth, which is also taught by His being called the brightness of the Father (for there is nothing round about the sun but its brightness which is produced from it), what is there in the Old Testament more plainly and obviously in accordance with this than the words, "Your truth is round about You?" Once more, Wisdom herself says in the gospel, "No man comes unto the Father but by me;" and the prophet says, "Who knows Your mind, unless You give wisdom?" and a little after, "The things pleasing to You men have learned, and have been healed by wisdom."
29. Paul says, "The love of God is shed abroad in our hearts by the Holy Spirit which is given unto us;" and the prophet says, "The Holy Spirit of knowledge will shun guile." For where there is guile there is no love. Paul says that we are "conformed to the image of the Son of God;" and the prophet says, "The light of Your countenance is stamped upon us." Paul teaches that the Holy Spirit is God, and therefore is no creature; and the prophet says, "You send Your Spirit from the higher." For God alone is the highest, than whom nothing is higher. Paul shows that the Trinity is one God, when he says, "To Him be glory;" and in the Old Testament it is said, "Hear, O Israel, the Lord your God is one God."
Source: On the Morals of the Catholic Church (New Advent)