While Unitarians focus on the love of God, decretal theologians focus on the sovereignty of God. They see God’s sovereignty as His defining characteristic. All other attributes are to be understood through the prism of God’s sovereignty and that He decreed certain things from eternity.
Perhaps the view that “God so loved the world” means “God so loved the elect” can be established from other texts. But proper exegesis rules out this interpretation…
According to the Calvinistic system of interpretation, all of humanity is born in such a condition (by God’s unchangeable eternal decree) where by they can read all the books offered up by the false religions of the world and accept them as truth, put their trust in their lies, and even affirm them as being divinely authored. But, mankind is born incapable of accepting or affirming the claims of Christianity unless causally determined to do so by irresistible spiritual means.
The term sovereignty, as a general word outside of Christianity and as a theological concept outside of Calvinism, has never meant what the Calvinist claims it means (a synonym for their doctrines).
Because the Calvinistic system affirms that God is willing to unchangeably decree and use self-deceived individuals to be objects of divine wrath in order to bring Himself more glory, it is impossible for any consistent Calvinist to be certain that he or she is not one chosen for this ignoble purposes.