http://www.reformation21.org/blog/2015/11/defending-the-covenant-of-rede.php
http://www.reformation21.org/blog/2015/11/defending-the-covenant-of-rede-1.php
http://www.reformation21.org/blog/2015/11/defending-the-covenant-of-rede-2.php

Does the Covenant of Redemption Compromise Orthodox Trinitarianism? This is one of the criticisms Scott Swain answers leveled against covenant theology in a series of posts specifically on the covenant of redemption. The criticism leveled is that if there are multiple parties within the godhead who then make covenants with each other, the door is then open for heretical arguments of tritheism. Nothing could be further from the truth of scripture and reason as he shows. To see and grasp this doctrine from scripture is to see the beauty of God’s work in eternity in establishing the basis for the gospel, for from this everything else springs: the Father, Son and Spirit’s intentionality in carrying out the work of redemption. To unfold this doctrine is to unfold the very love of God Himself.