God is all-wise—eternally and unchangeably so. His wisdom is reflected both in his eternal plan and in all his ways and works. He has wise reasons for his determined ends even though those reasons may not always be apparent to the creature. The Catechism here also obviously intends to include within the category of wisdom the category of knowledge, since it is not mentioned elsewhere in the definition. In other words, God knows all things and all true propositions (omniscience), always has and always will know all things, and cannot learn more or forget anything he knows. The Scriptures are replete with such teaching:
1 Samuel 2:3: “Do not keep talking so proudly or let your mouth speak such arrogance, for the Lord is a God who knows, and by him deeds are weighed.”
1 Samuel 16:7: “Man looks at the outward appearance, but the Lord looks at the heart.”
Job 37:16: “Do you know how the clouds hang poised, those wonders of him who is perfect in knowledge?”
Psalm 33:13: “From heaven the Lord looks down and sees all mankind; from his dwelling place he watches all who live on earth—he who forms the hearts of all, who considers everything they do.”
Psalm 94:9–11: “Does he who implanted the ear not hear? Does he who formed the eye not see? Does he who disciplines nations not punish? Does he who teaches man lack knowledge? The Lord knows the thoughts of man; he knows that they are futile.”
Psalm 104:24: “How many are your works, O Lord! In wisdom you made them all.”
Psalm 139:1–4, 15–16: “O Lord, you have searched me and you know me. You know when I sit and when I rise; you perceive my thoughts from afar. You discern my going out and my lying down; you are familiar with all my ways. Before a word is on my tongue you know it completely, O Lord.… My frame was not hidden from you when I was made in the secret place. When I was woven together in the depths of the earth, your eyes saw my unformed body. All the days ordained for me were written in your book before one of them came to be.”
Proverbs 8:22–23, 27–30: “The Lord brought me [that is, wisdom] forth as the first of his works, before his deeds of old; I was appointed from eternity, from the beginning, before the world began.… I was there when he set the heavens in place … and when he marked out the foundations of the earth. Then I was the craftsman at his side.”
Proverbs 15:3: “The eyes of the Lord are everywhere, keeping watch on the wicked and the good.”
Isaiah 40:13–14: “Who has understood the Spirit of the Lord, or instructed him as his counselor? Whom did the Lord consult to enlighten him, or who taught him the right way? Who was it that taught him knowledge or showed him the path of understanding?”
Isaiah 40:27–28: “Why do you say, O Jacob, and complain, O Israel, ‘My way is hidden from the Lord; my cause is disregarded by my God’? Do you not know? Have you not heard? The Lord is the everlasting God, the Creator of the ends of the earth. He will not grow tired or weary, and his understanding no one can fathom.”
Isaiah 46:10: “I make known the end from the beginning, from ancient times, what is still to come.”
Romans 11:33–36: “Oh, the depth of the riches of the wisdom and knowledge of God! How unsearchable his judgments, and his paths beyond tracing out! Who has known the mind of the Lord? Or who has been his counselor?”
Romans 16:27: “To the only wise God be glory forever through Jesus Christ! Amen.”
Hebrews 4:13: “Nothing in all creation is hidden from God’s sight. Everything is uncovered and laid bare before the eyes of him to whom we must give account.”
1 John 3:20: “God is greater than our hearts, and he knows everything [γινώσκει πάντα, ginōskei panta].”
Thus the all-wise God is at every moment cognizant of everything that ever was, now is, or ever shall be. And it has never been otherwise.
Source: Reymond, R. L. (1998). A new systematic theology of the Christian faith.