However, joy is an essential part of being Christian, but this joy is not something we “create,” but something we “receive.”
St. Paul VI wrote an entire encyclical on joy entitled, Gaudete in Domino. In it, he explains the characteristics of Christian joy and how we can dispose ourselves to receive such a gift.
First of all, Paul VI describes the basic definition of Christian joy.
In essence, Christian joy is the spiritual sharing in the unfathomable joy, both divine and human, which is in the heart of Jesus Christ glorified…Paschal joy is not just that of a possible transfiguration: it is the joy of the new presence of the Risen Christ dispensing to His own the Holy Spirit, so that He may dwell with them. The Holy Spirit is given to the Church as the inexhaustible principle of her joy as the bride of the glorified Christ…Joy is the result of a human-divine communion, and aspires to a communion ever more universal. In no way can it encourage the person who enjoys it to have an attitude of preoccupation with self. Joy gives the heart a catholic openness to the world of people, at the same time that it wounds the heart with a longing for eternal bliss.
This type of joy resides in the heart of God himself and can only be attained when we are in union with him. While we may experience glimpses of this joy on earth, it will see its realization only in Heaven.
The saints attest to this joy, even in the midst of very severe trials.
And then how could one fail to recall the luminous figure and example for our generation of [Saint] Maximilian Kolbe, the authentic disciple of St. Francis? In the most tragic trials which have bloodied our age, he offered himself voluntarily to death in order to save an unknown brother, and the witnesses report that his interior peace, serenity and joy somehow transformed the place of suffering—which was usually like an image of hell—into the antechamber of eternal life, both for his unfortunate companions and for himself.
Above all, this peace and joy the saints experienced was made possible through abandonment to God and his will.
St. Therese of Lisieux shows us the courageous way of abandonment into the hands of God to whom she entrusts her littleness. And yet it is not that she has no experience of the feeling of God’s absence, a feeling which our century is harshly experiencing; “Sometimes it seems that the little bird (to which she compared herself) cannot believe that anything else exists except the clouds that envelop it …. This is the moment of perfect joy for the poor, weak little thing …. What happiness for it to remain there nevertheless, and to gaze at the invisible light that hides from its faith.”
If we want to be truly joyful in this life, we need to understand that joy does not come from within us, or by seeking the earthly pleasure of passing things, but by finding that joy in God and letting him enter our soul.