“The person who performs a mitzvah, who prays or directs his mind toward the Divine, in doing so creates an angel, which is a sort of reaching out on the part of man to the higher worlds.
Such an angel, however, connected in its essence to the man who created it, still lives, on the whole, in a different dimension of being”
From The Thirteen Petalled Rose, p. 11 by Rabbi Adin Steinsaltz