Revelation and redemption go together; they are inseparable. Revelation normally both precedes and follows redemption; and revelation always causes redemption (I am speaking of the application of redemption). Revelation is not simply the imparting of raw data, but the knowledge of a Person (v. 27). Revelation is not something we seize, but something God graciously gives.
Here we see God withholds revelation from the “wise” and gives revelation to little children. The “wise” are those who have a form or worldly wisdom, in opposition to the wisdom that comes from God. It is a wisdom ignorant of God, apart from God, and in opposition to God. Specifically it looks at God’s redemptive revelation and thinks it foolish (cf. 1 Corinthians 1:18-2:16). So just as the “righteous” in Matthew 9:11-12 are not really righteous, so here the “understanding” don’t understand. They don’t understand for two reasons: sin within, and revelation withheld (Matthew 11:20-24).
It is important to realize that God’s hiding and revealing are not symmetrical. God’s does not hide and reveal in the same way. God positively gives light, but He does not positively give darkness. God’s hiding is an act of judgment on those who do not wish to see; His revealing is an act of grace on those who do not deserve to see. Thus Jesus denounces the cities for their unbelief and praises God for hiding revelation from them. God does not hide revelation from men who are otherwise trying to find Him. No one is trying to find Him (Romans 3:11). God is the predator, we are the prey. If we refuse it is due to darkness within. If we come is is due to light from without.
Revelation as an act of grace is not merited by definition. Grace is undeserved. No one has a right to it. Only judgement is merited. Some get justice, some get mercy, no one gets injustice. The astounding thing is not that God chooses some, but that He chooses any. If we are undeserving, why does God reveal to any at all? Because it is His “good pleasure” (v. 26 NIV). In Luke this is even more apparent as Jesus thanks God rejoicing in the Holy Spirit (Luke 10:21).
Imagine the proudest Father, and the most deluded son. Picture that father who already believes that his son is the next hall of famer even though he is only six years old, and his son who thinks his dad is some genius-millionaire-superhero; and then magnify their delight and delusions to infinity. Then realize that God the Father, and God the Son are like this, yet they never exaggerate the other. The Father’s Son really is perfect, the Son’s Father really can do anything, and they both want you to know it! The Father wants you to be thrilled at His Son, the Son wants you to marvel at His Father, and they send the Holy Spirit to open your eyes. You are saved because God is so happy in Himself. The entire Trinity rejoices in redemptive revelation. You were redeemed in joy, now joy in your redemption.