19 But this very mildness and simplicity which characterize their rule ought to inspire the observance of it with such great love of God that the Sisters who glory in their title, Daughters of St. Francis de Sales, may become known for their perfect abnegation of self and for their humble obedience at all times. They, therefore, should do everything possible to acquire a solid and not a merely superficial virtue and to die always to themselves in order to live only for God. Is there anyone who cannot recognize in their manner of life that union of strength and meekness which is so much to be admired in St. Francis himself, their holy Founder?
Source: Rerum Omnium Perturbationem (Vatican.va)