An extract from "In His Presence" by Louis Evely, thanks to Easter Triduum readings compiled by Fr Christopher Soh, sj:
"THE GREAT VIRTUE we should exercise during Paschaltide (traditional term for Easter season) is joy. At every moment the prayer of the Church at Mass or in the Office is interrupted by cries of joy, by endless Alleluias. And Jesus tells us that this joy is what will distinguish us from "the world": "Yet a little while," he said on the eve of his Passion, "and the world will see me no longer; but you, you will see me, I shall see you again and your heart will rejoice and no one will take your joy from you."
"Now the odd thing is that we are not in tune with this joy. We are more ready to sorrow with Christ than to rejoice with him; we find it easier to share his sufferings than his joy.
"The greatest sacrifice and most searching renunciation that we must offer to God is to be happy."
"... WE ARE MORE READY to afflict and mortify ourselves with our Lord than to rejoice in his resurrection, because what we are looking for in suffering is ourselves, what we so easily find is ourselves: our naturally pessimistic turn of mind is in tune with those tragic events, and we always have good reasons for being sad on our own account which allow us to feel sorry for ourselves while appearing to feel sorry for him.
"But to share in the joy of another, that is the occasion and the sign of a genuine devotion and disinterestedness, because it is a joy in which there is nothing of us, a joy in which we find so little of ourselves.
"After Lent, the greatest mortification of all is still to come, the greatest renunciation of all still has to be made, the one prepared by all the others and the touchstone of their authenticity: We must offer God the sacrifice of being happy. We must give God the joy and reward of seeing us happy, of telling him that after all he has done and suffered on our behalf, there really is nothing else we can live on save the joy of his love; we are bound up with him, united to him, live by him, so that when we look into the depths of ourselves, we find that nothing in us is more living than his joy."
"Happy the people who know the joyful shout; in the light of your countenance, O Lord, they walk." -- Psalm 89:16
Bl. Teresa of Calcutta in A Gift for God (as quoted in Living Faith):
"Joy is prayer; joy is strength; joy is love; joy is a net of love by which you can catch souls. God loves a cheerful giver. She gives most who gives with joy. The best way to show our gratitude to God and the people is to accept everything with joy. A joyful heart is the inevitable result of a heart burning with love. Never let anything so fill you with sorrow as to make you forget the joy of Christ risen.
"We all long for heaven where God is, but we have it in our power to be in heaven with him right now -- to be happy with him at this very moment. But being happy with him now means:
loving as he loves,
helping as he helps,
giving as he gives,
serving as he serves."