John of the Cross was asked by Teresa of Avila to follow her — which he did.  Both  Teresa and  John  were 16th century Catholic  mystics living in Spain.
St. Teresa of Avila was a writer, reformer and mystic who started the Carmelite order.
St. John of the Cross, famous for Spiritual Canticle, wrote Dark Night of the Soul while he was locked in a 6′ by 10′ cell. Both of these  were written in Spanish.  At that time,  the Bible was only available in Latin.
At age 43, Teresa of Avila started her first convent  and later  several other convents for women. She created a rule for how the women  were to live, committed to a simple life of poverty based on love.
“The important thing is not to think much but to love much and so do that which best stirs you to love. Love is not great delight but desire to please God in everything.†(1)
John of the Cross created a similar way of life in  living together  for men.  John of the Cross  served as Teresa’s spiritual director and confessor.