If there ever was a song that summed up St. Vincent de Paul's spirituality and the charism of the Daughters of Charity, it would be this one ("The Face of Christ" by Chris Rice):
Sr. Denise used this song after a reflection at our young adult meeting, in which we visited a house of the Daughters of Charity. The whole reflection, led by another Sister, was on Matthew 25: 31-36, which was essentially the basis for St. Vincent de Paul and consequently St. Louise de Marillac, the founders of the Daughters of Charity, the first successful religious community to live outside the cloister. This is the whole Vincentian charism - to see and serve Christ in the poor.
The Constitutions, almost 400 years later, continue to echo this sentiment - the poor are our masters because their face is the face of Christ's - not just as an afterthought, but rather as the theme and foundation of the whole community and the reason for their unique fourth vow: complete service to the poor.
"The King will reply: 'Truly, I tell you, whatever you did for the least of these brothers and sisters of mine, you did for me.'" - Matthew 25:40