6 But since he spurned the pomps and vanities of the world, and earnestly strove after "the greater gifts," with the object of progressing more rapidly along the road to perfection, he gladly offered himself, when a youth of nineteen years, to the Society of Jesus, and was received into the noviceship, then at Vilna. He remembered that solemn warning of Jesus Christ, "If anyone wishes to come after Me, let him deny himself, and take up his cross daily, and follow Me," and so daily strove more eagerly to acquire the virtue of Christian humility by contempt of self.
Source: Invicti Athletae (Vatican.va)