“Because of this, and hearing of your faith in the Lord Jesus and the love you have toward all the saints, I do not cease to give thanks for you, making remembrance of you in my prayers in order that the God of our Lord Jesus Christ, the Father of Glory, would give you a spirit of wisdom and revelation in the knowledge of him.”
For what does Paul pray when he gives thanks for the Ephesian church? His prayer is that God would give to the the spirit of wisdom and revelation in the knowledge of God. This does not so much seem to be a matter of the Holy Spirit (hence we have not capitalized the noun, plus there is no definite article); they already have the Holy Spirit as he is the one who converted them and made them believers in the first place. No, it is so that they would have a spirit of wisdom and that they would have a spirit of revelation.
We have already discussed wisdom at length, but this is just one more reminder of the importance that the Bible places upon wisdom as well as the source of that wisdom, which is the fear of the Lord (Proverbs 9:10). You can have no authentic wisdom if you do not first approach God with fear and reverence. As the psalmist states, nothing but sin results from the lives of those who do not fear God.
“Transgression utters to the wicked in the depth of his heart;
there is no dread of God before his eyes.”
(Psalm 36:2 — verse 1 in English translations)
The second thing for which Paul prays is for a spirit of revelation. We often think of revelation — ἀποκάλυψις (apokalupsis) in the Greek — in terms of the Revelation of Jesus to John that closes our Canon. Because of that, we often only think of revelation in terms of end times things. To be fair, Paul does use this term in such a way (cf. Romans 8:19; 2 Thessalonians 1:7), but he also uses it to speak of God’s revelation to him (Galatians 1:12), and in terms of the full revealing of the Gospel (Romans 16:25). That seems to be the context in which he is using the term here — in other words, that God would more and more reveal to their understandings the magnificent outworking of His Gospel.
Don’t miss the clarification at the end of the verse, though. Paul is praying for the spirit of revelation for the Ephesian church, but that such revelation always be in the knowledge of God. Indeed, how important this principle is, for anything received or held without the knowledge of God is in vain and worthless. As I look around at the evangelical world today, it strikes me at just how often knowledge of God is downplayed. As a result, this generation is without fear of the Lord even in the bodies that proclaim themselves to be churches (for many are not!). Paul makes it abundantly clear that knowledge, to be of any value, must first and foremost be of God. Plenty of people have knowledge of the world but the world is passing away. The things of God are eternal.