Typically, in the ‘Classic Calvinist’ framing of the atonement, the ‘ground’ of God’s love for humanity is predicated upon Christ’s legal payment of restitution at the cross. In other words, God is able to love ‘sinners in the hands of an angry God’ because Christ meets the obedience requirements set out in the ‘Covenant of Works’. God’s love for us is contingent upon the legal payment made at the cross in this scenario.
TF Torrance comments on a different approach, in fact an ‘Evangelical Calvinist’ approach, offered by a Scottish theologian named John Davidson. Torrance is commenting on Davidson’s catechism, and upon the ground of God’s love for us:
. . . All through his Catechism Davidson laid the strongest emphasis upon what has taken place in the Person of Christ apart from believers, and never upon the persons of those who believe. This was coupled with his emphasis upon the prevenient love of God, from which salvation flowed, without any suggestion that God had to be placated or appeased in order to love and be gracious toward sinners. [Thomas F. Torrance, “Scottish Theology,” 54]
The broader discussion here is on Davidson’s understanding of union with Christ, and of course that vicarious relationship that obtains in Christ’s life for us. But beyond that, this illustrates an important point of departure (and I realize some want to see more uniformity between Federal and Scottish or Evangelical Calvinism — but these are the material points), between a Federal Calvinist and an Evangelical Calvinist, so called. In the latter’s case, we see the cross and Christ’s death, therein, as driven or predicated by God’s love for us in Christ; in the former, they see God’s love for us predicated by certain forensic stipulations being met prior to God’s ability to love us [albeit framed decretally or through the decrees].
Let me rephrase, for sake of clarity; The ‘Federal Calvinist’ makes God’s love for ‘elect’ humanity a byproduct of something else being met first, viz. the the penalty for ‘Law-breaking’ — the ‘ground’ of His love is that the requirements of the ‘Law’ are met (thus the ‘Law’ becomes determinative of who God is, instead of God determining who He is). The Evangelical Calvinist says that God in Christ first loved us (in His intratrinitarian life), and that God’s life of love becomes the ‘ground’ for His actions in salvation history. The cross is a demonstration of God’s love, not the predicate (def. of ‘predicate’ is: ” involve as a necessary condition of consequence” def. taken from here) of God’s love. Federal theology says the latter is true, Evangelical Calvinism says the former is. The Apostle Paul agrees with the Evangelical Calvinist on this point:
But God demonstrates His own love toward us, in that while we were yet sinners, Christ died for us. ~Romans 5:8 (NASBU)
This topic actually is illustrative of what differentiates an Evangelical Calvinist approach from the Federal approach — it is the ‘Doctrine of God’. I believe that Federal theology makes God a predicate of creation; and then I also believe that Evangelical Calvinism sees God as He is, the antecedent of creation (He is in Himself, without us . . . cf. Ex. 3:15). Torrance continues to comment on the presupposition of Davidson’s thought vis-a’-vis Federal theology, he says:
It was Davidson’s statement that ‘Faith is ane heartie assurance that our sinnes are freely forgiven us in Christ’, that appeal was to be made again and again in Scottish theology in face of the lack of assurance that came with the change in the doctrine of God brought about by federal theology and the idea that God had to be appeased in order to be gracious to us. With Davidson, however, the assurance of salvation which is identical with faith is ultimately grounded in ‘the tender mercy and grace of God, who loving us when we were his enemies, provyded our salvation to bee wrought onely by his wellbeloved Sonne Jesus Christ, made Man of the Virgine Marie without sinne.’ That is to say, it was from the ultimate love of God the Father in freely giving his Son to be our Mediator, Redeemer and Saviour, that all parts of our salvation are fully accomplished in such a way in Christ that nothing on our part can ‘deface the assurance of our salvation’. . . . [TFT is quoting Davidson’s old Scottish] [Torrance, 54-55].
Here Torrance illustrates the significance that a ‘doctrine of God’ can have upon all kinds of doctrine — especially, of course, salvation — least of which is the atonement. This continues to illustrate a certain distinctiveness between Evangelical Calvinism and Federal Calvinism . . . it orbits around different doctrines of God, and then different understandings of salvation, etc.