One of the things we talked about in the Systematic Theology class a few weeks ago was angels, including what they are, how they function, and what they know and don’t know.
Writing about good angels in today’s blog, John Piper notes that it is clear angels are not omniscient — that they are always learning. Despite being perfect, these created beings still learn.
The significance of this truth? “I cannot think of any reason to think there will ever come a point in eternity when finite minds will have infinite knowledge,” says Piper.
In other words, angels and all created beings (i.e., redeemed mankind) in heaven will forever be learning.
Part of what makes “eternal life” satisfying (and not boring) forever is that it will take an eternity for perfect, finite creatures like us to know God fully. He is perfect and infinite. We will be perfect and finite. He will enjoy increasing revelation of himself, and we will enjoy increasing jubilation in him—forever.[Piper]
This coincides with one of my favorite verses: “so that in the ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus” (Eph. 2:7).
In other words, for all of eternity, God will be unfolding the richness of His grace as it was mantifested in our lives — always demonstrating just how gracious He has been in producing our salvation. How little we must comprehend of our salvation if God can reveal more and more of what He has done, and in all the vast extent of eternity, we will never come to a complete knowledge of that salvation!
As Ryle noted, “Well might George Whitfield say, ‘The anthem in heaven will be, “What hath God wrought!”‘”
Words of Grace 
Then the angels stand and listen, for they cannot join the song,
Like the sound of many waters, by that happy, blood washed throng,
For they sing about great trials, battles fought and victories won,
And they praise their great Redeemer, who hath said to them, “Well done.”