These are all Calvinist theories, in which I have no interest. I do what Christ and His apostles tell us. You are curious what is it, I'll tell you, but it looks like you can read NewAdvent for yourself. That is a good start.
As so often happens, New Advent contradicts Scripture and Jesus Christ Himself...
And all mine are thine, and thine are mine; and I am glorified in them." -- John 17:9-10"I pray for them: I pray not for the world, but for them which thou hast given me; for they are thine.
Salvation - It begins with the grace of God which touches a sinner's heart, and calls him to repentance. This grace cannot be merited; it proceeds solely from the love and mercy of God. Man may receive or reject this inspiration of God, he may turn to God or remain in sin. Grace does not constrain man's free will. Thus assisted the sinner is disposed for salvation from sin; he believes in the revelation and promises of God, he fears God's justice, hopes in his mercy, trusts that God will be merciful to him for Christ's sake, begins to love God as the source of all justice, hates and detests his sins.(New Advent)
25 And when you shall stand to pray, forgive, if you have aught against any man; that your Father also, who is in heaven, may forgive you your sins. 26 But if you will not forgive, neither will your Father that is in heaven, forgive you your sins.(Mark 11)