God is "madly in love" with us, said the medieval mystic and activist Catherine of Siena, and when we finally realize this truth, we'll discover that loving others is irresistible. Her Dialogue, prayers, and letters teach us to be alone with God in "the cell of our soul." Only then are we ready for public service.

Her own life followed this path. Born Caterina Benincasa (1347-1380), she was the 24th  of 25 children in an Italian wool dyer's family. She dedicated herself to Christ as a child and at 16 took the habit of a Dominican lay sisterhood. After being disfigured by small pox, she chose a time of solitude at home. For three years, she spoke little, praying instead. Then, at 21, she experienced a spiritual union with God that she described as a "mystical espousal" to Christ. It changed her focus. She left behind her solitary life and embraced a real activism in the world. Although she lived in physical pain every day, she dedicated her remaining 12 years to caring for the sick and serving the poor. St. Catherine of Siena died in Rome at the age of 33, still trying to reform the church.

The following excerpts from her writings challenge us in incredibly modern ways to grow up spiritually.

A prayer for goodness

Indescribable love! Open our memory up for us, so we can receive, remember, and grasp the great goodness of God. As much as we understand God's goodness, we'll love, and whenever we love, we find ourselves in union with and transformed by that love. The mother of all virtues is love. This love passed through and always passes through the gate that is Christ crucified.

Love's celestial Cement

Sweet, measureless love, who moved you? Love alone. O gentlest love, Jesus! To strengthen each person's soul and free it from the weaknesses it fell into knowing through disobedience, you built a wall around it, mixing the flow of your own blood into the lime for the mortar. This blood fuses the soul with God's gentle, divine will and fits it for his love because just as lime mixed with water is put between stone and stone to bind them together securely, so God mixed the blood of his only-begotten Son into the living lime, the fire of his shining love. God put this celestial cement between himself and every one of his creatures—because there is no blood without fire, nor fire without blood.

From darkness to light

Eternal Trinity, help me stay awake. Don't ever let me turn again to that miserable life I once led in the darkness, through no fault of your own. I didn't know your truth then, so I didn't love it. But I do now. Why didn't I know you then? The cloud of self-centered love darkened the eye of my understanding, but you came with your light, Eternal Trinity, and banished all the darkness in me!

How love feeds our souls

Love gives her children milk. Love feeds her children well. We get this milk in the same way a baby sucks milk from its mother's breast. We get our nourishment by sucking milk through Love's nipple. Just so, our soul can have life only through Christ crucified. Jesus tells us in the Gospel of John that no one can come to the Father except through him. Also in this Gospel he tells us that he is the way, the truth, and the life, and that whoever walks with him doesn't walk in the darkness, but in the Light. Walk in that Light.

God as our bail bond agent

Let our hearts and souls explode with love! Let them run to serve our good sweet Jesus, and respect him. Let them remember how Christ rescued us from prison and from the devil who had us in his power. Our Lord became our bail and surety for us. God himself tore up the deed of bond. When? When Jesus became a servant. When God assumed our own humanity. Still, not even that was enough. Christ had to pay the debt incurred on our behalf. Again, when? On the wood of the most holy Cross. O sweet, incomparable, immeasurable Love!

Advice on learning to love again

I know you're going to ask me, since I talk so much about agape love, "But what if I have no such unconditional love in me and no great tenderness (and I don't), and yet you say without such love I'm powerless; so then, how can I get it?" I'll tell you how. Love is only had by loving. So be up and doing. Remember—there's nothing so difficult and no stronghold so impregnable that it can't be broken down (and you built up) by Love.

Carmen Acevedo Butcher is associate professor of English and scholar-in-residence at Shorter College in Rome, Georgia.

Read more wise advice by Catherine of Siena and other women mystics in A Little Daily Wisdom by Carmen Acevedo Butcher (Paraclete Press, 2008). For more background information, see Carol Lee Flinders's excellent Enduring Grace: Living Portraits of Seven Women Mystics (HarperCollins Publishers, 1993, p. 104) and Thomas McDermott's Catherine of Siena: Spiritual Development in Her Life and Teaching (Paulist Press, 2008) and his splendid website, Drawn by Love.