In his spiritual ascent, Father Triest was certainly inspired by the medieval mystics. A figure like John of Ruysbroeck was surely not unfamiliar to Triest. His texts reveal almost literal quotations when he writes of divine love that makes his heart burn.
During his time in the seminary, he became acquainted with Saint Francis de Sales and Saint Vincent de Paul. These contemporaries of the 17th century made their mark on French spirituality. As bishop, Francis held a plea that everyone was called to holiness and tried to start an all-new community of sisters who would nurse the sick at home. However, his Sisters of the Visitation had to observe the cloister and eventually became enclosed nuns.
Vincent de Paul was deeply influenced by Francis de Sales and developed a whole new view of charity. He saw the poor as his Lords and Masters, who had to be served with love and respect, and he called on all to see the living icon of Christ in every poor person. Vincent would breathe new life into charity, especially with the foundation of the Daughters of Charity, who were committed to the care of the poor.