Circumincession in Latin and perichoresis in Greek affirm the reciprocal existence of each Person of the Trinity in the other two Persons. Where one Person acts, all three act.
"Do you not believe that I am in the Father and the Father is in me? The words that I speak to you I do not speak on my own. The Father who dwells in me is doing his works. Believe me that I am in the Father and the Father is in me, or else, believe because of the works themselves" (Jn 14:10-11).