Do not cease to pray for you. — Comp. Ephesians 1:16. “To pray” (see Ephesians 6:18; Philippians 4:6) is the general word for “to worship”; “to desire” indicates prayer, properly so called, asking from God what is requisite and necessary for ourselves or for others.
The knowledge of his will. — The “knowledge” here spoken of is the “full knowledge,” to be attained in measure here, to be made perfect in heaven. See 1 Corinthians 13:12, “Now I know in part; but then shall I know (perfectly) even as I am known.” On this word, especially frequent in the Epistles of the captivity, see Note on Ephesians 1:17. It should be noted that the knowledge here prayed for is “the knowledge of God’s will” — not speculation as to the nature of God, or as to emanations from Deity, or even as to the reasons of God’s mysterious counsels, but knowledge of what actually is His will, both in the dispensation which is to be accepted in faith, and in the commandments to be obeyed in love. So St. Paul (in 1 Timothy 1:4-5) contrasts with the “fables and endless genealogies” of Gnostic speculation, “the end of the commandment,” “charity out of a pure heart and a good conscience, and faith unfeigned.”
In all wisdom and spiritual understanding. — This “knowledge of God’s will” is man’s “wisdom.” For “wisdom” is the knowledge of the true end of life; which is (as the Book of Ecclesiastes so tragically shows) vainly sought, if contemplated apart from God’s will, but found (see Ecclesiastes 12:13; Job 28:28; Proverbs 1:7) in the “fear of the Lord” and the “keeping of His commandments.” (On the relation of the supreme gift of wisdom to lesser cognate gifts, see Note on Ephesians 1:8.) “Understanding” here is properly the faculty of spiritual insight or judgment, the speculative exercise of wisdom, as the “prudence” of Ephesians 1:8 is the practical. Hence St. Paul subjoins the practical element at once in the next verse.