All double predestination means is that God is sovereign and He chooses His children and who will be with Him in Heaven. It is opposed to the idea that man is the one who chooses whom are God's children and will be with Him in Heaven. I am unaware of any concept of dualism that would include God choosing alone in His sovereignty what He alone has the right to choose.
FK-””That is why I used the phrase “glorifying the merit of man”. If getting into Heaven is the name of the game, then it cannot be accomplished without the key ingredient of man’s merit.””
Perhaps you don’t understand what the Church teaches regarding merit. From the Catechism...
...... 2008 The merit of man before God in the Christian life arises from the fact that God has freely chosen to associate man with the work of his grace. The fatherly action of God is first on his own initiative, and then follows man’s free acting through his collaboration, so that the merit of good works is to be attributed in the first place to the grace of God, then to the faithful. Man’s merit, moreover, itself is due to God, for his good actions proceed in Christ, from the predispositions and assistance given by the Holy Spirit. (emphasis added)
2009 Filial adoption, in making us partakers by grace in the divine nature, can bestow true merit on us as a result of God’s gratuitous justice. This is our right by grace, the full right of love, making us “co-heirs” with Christ and worthy of obtaining “the promised inheritance of eternal life.”60 The merits of our good works are gifts of the divine goodness.61 “Grace has gone before us; now we are given what is due. . . . Our merits are God’s gifts.”62 (emphasis added)
I really may not understand what the Church teaches here as I find these two sections completely contradictory. One shares credit between God and man's free will (meaning will that has not been under God's control), and the other somehow gives all the credit to God. These would appear to be mutually exclusive ideas, but I have thought that the actual position of the Church is really the first. It would be a misnomer to refer to "man's merit" if the truth is that it is "God's merit through man". Plus, free will choice requires partial independent credit for man alone. Otherwise it would not be free will.
“”All double predestination means is that God is sovereign and He chooses His children and who will be with Him in Heaven.””
Everyone is chosen to be God’s children,it’s our free decisions that send us to hell and has nothing to do with God sovereignty deciding from eternity.God can only desire goodness in creation since that is His essence.Hell is completed connected to mans decisions to do evil
“Thou lovest all things that are, and hatest nothing of the things that Thou hast made” (Wisd. xi, 25)
From the words of the late blessed Pope JPII...
“Eternal damnation”, therefore, is not attributed to God’s initiative because in his merciful love he can only desire the salvation of the beings he created. In reality, it is the creature who closes himself to his love. Damnation consists precisely in definitive separation from God, freely chosen by the human person and confirmed with death that seals his choice for ever. God’s judgement ratifies this state.
FK-””I really may not understand what the Church teaches here as I find these two sections completely contradictory. One shares credit between God and man’s free will (meaning will that has not been under God’s control)””
Nothing contradictory,dear brother. Man moved by Grace can accept that Grace and freely follow God’s will,thus man synergistically WITH GOD does good works enlightened by the Holy Spirit being fully aware and wanting to participate with God through that synergism with God.
A few words from Church Fathers...
“When effort on our part is absent, then God’s help also stops.” Saint John Chrysostom
“God works together with willing souls. But if the person abandons his eagerness, the spirit from God is also restrained. To save the unwilling is the act of one using compulsion; but to save the willing, that of one showing grace.” 190 AD St. Clement of Alexandria Salvation of the Rich Man chap. 21