There are multiple characters and events which are memorable, including the expansion of the Lord’s prayer (Purgatorio, Canto XI, p252) and Virgil’s discourse on the nature of love while in the Terrace of the Slothful (Purgatorio, Canto XVIII, p290), which is also the geographic center of the Comedy (as Dr. Gage stated).
tempers our will and makes us want no more
than what we have - we thirst for this alone.
If we desired to be higher up,
then our desires would not be in accord
with His will Who assigns us to this sphere;
think carefully what love is and you'll see
such discord has no place within these rounds,
since to be here is to exist in Love.
Indeed, the essence of this blessed state
is to dwell here within His holy will,
so that there is no will but one with His;
the order of our rank from height to height
throughout this realm is pleasing to the realm,
as to that King Who wills us to His will.
In His will is our peace - it is the sea
in which all things are drawn that it itself
creates or which the work of Nature makes."
Then it was clear to me that every where
of heaven is Paradise, though there the light
of Grace Supreme does not shine equally.
As we all know, there are many passages which touch on these themes. A few that came to mind include thinking about God's will for us. Dante stated "the essence of this blessed state is to dwell in His holy will" and "in His will is our peace." Paul states more clearly what His will is for us: "For this is the will of God, your sanctification" (2 Thes 4.3). It is in our sanctification, in holiness, that we find and experience peace; growing in Christ-likeness, being conformed to His image, that when He appears, we shall be like Him. (1 Jn 3.2). And what is one attribute of God's character? Love. God is love (1 Jn 4.8). So as Dante states, "to be here [i.e. in Paradiso] is to exist in love."
Even more poignantly, Paul wrote " God, being rich in mercy, because of the great love with which he loved us, even when we were dead in our trespasses, made us alive together with Christ — by grace you have been saved — and raised us up with him and seated us with him in the heavenly places in Christ Jesus, so that in the coming ages he might show the immeasurable riches of his grace in kindness toward us in Christ Jesus." (Eph 2:4–7) We have the hopeful expectation of being seated with Christ in the heavenly places (i.e. Paradiso). We will dwell in peace with Him ("In His will is our peace"), and have no fear of rejection.
Though my heart and flesh may fail
There's an anchor for my soul
I can say "It is well" ...
When this darkness breaks to light
And the shadows disappear
And my faith shall be my eyes
No more sorrow, no more pain
I will rise on eagles' wings
Before my God fall on my knees
And rise
I will rise
(written Dec 7 2014)