WE LIVE in an age of relationship break-down. People dream of finding their "soul mate", but all too often it proves to be a mirage. Where can you turn for sound advice? Maybe the last person you'd think of would be a 12th century celibate monk! But Aelred's book, Spiritual Friendship, is as courageous and relevant today as it was in the 1150s.

"It is a great consolation," writes Aelred, "in this life to have someone you can unite with in an intimate affection; someone in whom your spirit can rest, to whom you can pour out your soul, who will bear with the weariness of your anxieties and search out with you the answers to your problems."

Aelred spent his whole life exploring the subject of brotherly love. As a young man at the royal court he felt a strong attachment to friends and happily spent hours in their company. Then he joined a monastic movement called the Cistercians, which was growing fast in western Europe. They had energy and vision, and enjoyed praising God. Their founder used to say "The best way to know God is to love Him", and love was the flavour of all they did.

Aelred's ability to love and to join people together was soon noticed and he was made abbot of a monastery at Rievaulx in Yorkshire. By the time he died in 1167 it had grown amazingly, to 600 members.

Aelred taught and wrote about friendship. He saw that love can be a woolly concept. People claim to have it, and to have friends, but in reality it is all shallow and self-centred. Daringly, he changes the well-known "God is love" to "God is friendship".

The way God relates to us through Jesus is the model for all relationships. Jesus, our pattern in all things, had His friends, like Martha, Mary and Lazarus; one is referred to as "the disciple whom Jesus loved" (John 21:20). Even the marriage of man and wife is modelled on the love-bond between Christ and the Church (Ephesians 5:32).

So, if we are to love one another in the way Jesus meant, love must go deep. We must become true heart-friends. Once chosen, such a friend deserves the best we can offer.

"One must care for one's friend, pray for him, grieve for his faults, support him when he is feeble, console him in sorrow, restrain him when he is angry, and correct him with love," writes Aelred.

Aelred teaches that we grow closer to God through such quality friendships, for we sense more of His own heart. On the other hand, "anyone without a friend is abandoned indeed". Aelred admits that even friendship must be tested, to see if it is truly "new creation" and not simply old-nature emotion. He encourages the brothers to delight in each other's company and to show affection (in all modesty). But he also stresses that friendship takes effort. After all, God might lead us to someone very different from ourself. Aelred flags up four key qualities: loyalty, discretion, patience and right intentions, all of which can be learned through the Holy Spirit and by practice.

Today, relationships are an "in" topic. "How-to" guides come and go. But probably none can match the inner honesty, happy warmth and visionary hope of this 12th century Yorkshire monk.