Karl Rahner writes:
"...the Trinity of the economy of salvation is the immanent trinity and vice versa. The 'economic' Trinity is the 'immanent' Trinity and the 'immanent' Trinity is the 'economic' Trinity." - Karl Rahner, The Trinity, p. 22.And Moltmann comments:
"That is why I have affirmed and taken up Rahner's thesis that 'the economic Trinity is the immanent Trinity and vice versa.' If the central foundation of our knowledge of the Trinity is the cross, on which the Father delivered up the Son for us through the Spirit, then it is impossible to conceive of any Trinity of substance in the transcendent primal ground of this event, in which cross and self giving are not present. Even the New Testament statement 'God is love' is the summing up of the surrender of the Son through the Father for us. It cannot be separated from the event of Golgotha without becoming false...What this thesis is actually trying to bring out is the interaction between the substance and the revelation, the 'inwardness' and the 'outwardness' of the triune God." - Jurgen Moltmann, The Trinity and the Kingdom of God, p 160.Quoted at AnCon 2004, Andrew Katay, The Cross of Christ: Infinite Justice, Infinite Mercy.