One of the people reputed most knowledgeable about the Word when he lived in the world had developed an idea of heavenly joy as consisting in a glorious ring of light like the circle of golden rays beaming from the sun. As in the previous example, this dream life of his involved inactivity. To awaken him to his misconception, he was granted this kind of light, and as he stood at its center he felt so much pleasure that, as he himself declared, it was like being in heaven. He could not linger there long, however, because little by little it grew tiresome for him and turned into no joy at all.
Some very well informed people claimed that heavenly joy lay in a life spent not in carrying out the good deeds prompted by charity but only in praising and celebrating the Lord. This life they called an active one. But I said that praising and celebrating the Lord is not an active life of the kind meant but a mere side effect of that life. The Lord has no need of praise but wants us to do the good things that charity calls on us to do. That is the activity that determines how happy the Lord can make us.
Those people, smart as they were, still could not find any promise of joy in the good deeds of charity, only the prospect of servitude. But to do such deeds is actually freeing and brings with it indescribable happiness, as the angels testified.
from Secrets of Heaven, Volume 1, Sections 455, 456