For Franciscan scholar Ilia Delio, compassion stems from knowing that we belong to one another:
I think our greatest fear is our deepest desire: to love and to be loved. We long to be for another and to give ourselves nobly to another, but we fear the cost of love. Deep within we yearn for wholeness in love, but to become more whole in love we must accept our weaknesses and transcend our limits of separation in order to unite in love. We long for oneness of heart, mind and soul, but we fear the demands of unity. Sometimes I think we choose to be alone because it is safe. To be comfortable in our isolation is our greatest poverty.
Compassion transcends isolation because the choice to be for another is the rejection of being alone. The compassionate person recognizes the other as part of oneself in a way that is mystical and ineffable. It is not a rational caring for another but a deep identification with the other as brother and sister. 
Delio stresses that compassion nourishes our interconnectedness with each other and the earth:
We must seek to unite—in all aspects of our lives—with one another and with the creatures of the earth. Such union calls us out of isolated existences into community. We must slow down, discover our essential relatedness, be patient and compassionate toward all living creatures, and realize that it is a shared planet with finite resources. We are called to see and love in solidarity with all creation. Only in this way can the earth enjoy justice and peace which means right, loving relations with the natural world of God’s good creation.
Compassion requires a depth of soul, a connectedness of soul to earth, an earthiness of person to person, and a flow of love from heart to heart. 
Recognizing our relatedness creates space within us that we wouldn’t otherwise find, and opens a deeper capacity to love:
Compassion is realized when we know ourselves related to one another, a deep relatedness of our humanity despite our limitations. It goes beyond the differences that separate us and enters the shared space of created being. To enter this space is to have space within ourselves, to welcome into our lives the stranger, the outcast, and the poor. Love is stronger than death and the heart that no longer fears death is truly free. Compassion flourishes when we have nothing to protect and everything to share. It is the gravity of all living beings that binds together all that is weak and limited into a single ocean of love.
We have the capacity to heal this earth of its divisions, its wars, its violence, and its hatreds. This capacity is the love within us to suffer with another and to love the other without reward. Love that transcends the ego is love that heals. When we lose ourselves for the sake of love, we shall find ourselves capable of real love. 
 Ilia Delio, Compassion: Living in the Spirit of St. Francis (Cincinnati, OH: St. Anthony Messenger Press, 2011), xvi.
 Delio, Compassion, 113.
 Delio, Compassion, 126.
Image credit: A path from one week to the next—Taylor Wilson, Transfiguration (detail), cyanotype, used with permission. Taylor Wilson, Madonna and Messiah, ink, used with permission. Alma Thomas, The Eclipse, acrylic on canvas, Smithsonian. Click here to enlarge image.
The rounded lines of mother and child echo the compassion we express toward others.
Story from Our Community:
I recently had an experience of seeing myself through God’s eyes. I was washing my hands when I happened to look up and catch my own gaze in the mirror. Something in me urged me to look deeply into my own eyes. All of a sudden, I was filled with both a deep sense of loving and an awareness of being loved. As I dried my hands and returned to my day, I walked away with a profound sense of gratitude and a desire to see this way always as the words of Matthew’s Gospel rang in my heart, “his heart was moved with compassion for them because they were troubled and abandoned” (9:36). —Sergio L.