For God is in all things by His essence, power, and presence, according to his one common mode, as the cause existing in the effects which participate in his goodness. Above and beyond this common mode, however, there is one special mode belonging to the rational nature wherein God is said is to be present as the object known is in the knower, and the beloved in the lover. And since the rational creature by its operation of knowledge and love attains to God Himself, according to this special mode God is said not only to exist in the rational creature, but also to dwell therein as in His own temple.
1.a.Q.43.art.3.Pt. 1, Summa Theologiae
"And the glory which thou hast given me, I have given to them; that they may be one, as we also are one: I in them, and thou in me; that they may be made perfect in one: and the world may know that thou hast sent me, and hast loved them, as thou hast also loved me. John 17:22-23
