This from Pope John Paul II's encyclical, Novo Millennio Ineunte:

The great mystical tradition of the Church of both East and West has much to say in this regard. It shows how prayer can progress, as a genuine dialogue of love, to the point of rendering the person wholly possessed by the divine Beloved, vibrating at the Spirit's touch, resting filially within the Father's heart. This is the lived experience of Christ's promise: "He who loves me will be loved by my Father, and I will love him and manifest myself to him" (Jn 14:21). It is a journey totally sustained by grace, which nonetheless demands an intense spiritual commitment and is no stranger to painful purifications (the "dark night"). But it leads, in various possible ways, to the ineffable joy experienced by the mystics as "nuptial union". How can we forget here, among the many shining examples, the teachings of Saint John of the Cross and Saint Teresa of Avila?

Yes, dear brothers and sisters, our Christian communities must become genuine "schools" of prayer, where the meeting with Christ is expressed not just in imploring help but also in thanksgiving, praise, adoration, contemplation, listening and ardent devotion, until the heart truly "falls in love". Intense prayer, yes, but it does not distract us from our commitment to history: by opening our heart to the love of God it also opens it to the love of our brothers and sisters, and makes us capable of shaping history according to God's plan.¹⁸