Love can be experienced as a painful reality. For St John of the Cross, God's touch in our lives, through the Holy Spirit, can cause a "love wound" that only God can heal. In his teaching, he likens the wound caused by God's love to the wounds created by the surgeon when operating on a person to remove something bad and make the person healthy again.

Those wounds and scars are unavoidable and necessary. They speak of the healing and new life experienced by the previously sick person. So it is with the wound of love that occurs when God, as a surgeon, operates in our soul. In that sense, the wound is beautiful and life-giving.

In one of his commentaries, John wrote:

O happy wound, wrought by one who knows only how to heal! O fortunate and most blessed wound; you were made only for the delight and gratification of the soul! . . . O then, delightful wound, so much more sublimely delightful the more the cautery touched the intimate centre of the soul, burning all that was burnable, in order to give delight!

It is unpopular nowadays to talk about a God whose love can cause us pain in our lives. We want to experience the love without having to put up with the pain. Yet, for St John, the way of love walked by Jesus was the way of the cross.

Allowing God to declutter within us all that is not life-giving, "burning all that is burnable", can be a painful experience, but it is essential if we seek to grow in our spiritual life. It is not all "doom and gloom", John says, for the same wound that causes the pain also brings the freedom, the healing, and the joy that our soul longs for.

It is also out of that experience of loving and being loved that St John affirms the centrality of love in a person's faith journey. Love, John believes, turns spiritual formation into spiritual transformation. Love alone can change us into the person that God created us to be.

Finally, love is the rule by which we will be "judged" at the end of our journey on this earth. John prefers to think of it as a loving examination. "When evening comes, you will be examined in love," he wrote.

In the evening of our life, when we come face to face with our Creator, God will not be interested in how many church services or Bible studies we have attended, or how successful or unsuccessful we were in our business. The Beloved will be interested in how much we loved, how selfless our love was, and how many people we touched with that love. That will be the final test, and that should be our ultimate motivation for life and for living.

For prayer and reflection

Some of the greatest women and men of God have lived this love-based spirituality, holding a newspaper in one hand and a Bible in the other (as Karl Barth put it).

Read the news in a paper or online, prayerfully, trying to identify the places where there is no love in the world or your community. Pray for love to fill those loveless situations, and for God to show you ways in which you can practically inject love into at least one of those places.

Then, allow God's living flame of love to rekindle your love for God and others by reading afresh the hymn of love in 1 Corinthians 13. Ask the Holy Spirit to empower you to live the sort of love that Paul describes in this passage.

This is the last of four edited extracts from Transformed by the Beloved: A guide to spiritual formation with St John of the Cross by Daniel Muñoz (BRF, £6.99 (CT Bookshop £6.29); 978-1-84101-584-2).