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. As soon as God the Father begins to manifest in history the mystery of His will according to His purpose which He set forth in Christ as a plan for the fullness of time, this joy is mysteriously announced in the midst of the People of God, before its identity has been unveiled. (Papal Writings, Gaudete in Domino: On Christian Joy, 9 May 1975)