"Be you therefore perfect, as also your heavenly Father is perfect."
ON UNION WITH GOD
CHAPTER I
OF THE HIGHEST PERFECTION WHICH MAN CAN ATTAIN UNTO IN THIS LIFE
I have felt moved to write a few last thoughts describing, as far as one may in this waiting-time of our exile and pilgrimage, the entire separation of the soul from all earthly things and its close, unfettered union with God.
I have been the more urged to this, because Christian perfection has no other end but charity, which unites us to God.[2]
This union of charity is essential for salvation, since it consists in the practice of the precepts and in conformity to the Divine will. Hence it separates us from whatever would war against the essence and habit of charity, such as mortal sin.[3]