I keep reading Acts 10, and I keep failing to find in the unregenerate Cornelius, "a religious man, and fearing God with all his house, giving much alms to the people and always praying to God", a hatred of God.
He was certainly still filled with such errors and misconceptions that "when Peter was come in, Cornelius came to meet him and falling at his feet adored." Yet scripture plainly calls him "a just man and one that feareth God."
Worse for your case, God told Cornelius He was going to give Him the Holy Spirit because "thy prayer is heard and thy alms are had in remembrance in the sight of God." Where are those "filthy rags" that avail us nothing here?
Sorry OP. You'll never win this point because you are WRONG.
"As, then, we ought not to depreciate a man's righteousness, which begins to exist before he is joined to the Church, as the righteousness of Cornelius began to exist before he was in the body of Christian men,--which righteousness was not thought worthless, or the angel would not have said to him, 'Thy prayers and thine alms are come up as a memorial before God;' nor did it yet suffice for his obtaining the kingdom of heaven, or he would not have been told to send to Peter ..." (St. Augustine, On Baptism, 4.21.29)
Sadly, you don't even really know the teaching of your beloved St. Augustine since you reject the Baptismal regeneration he plainly confessed. One must marvel at the contradictions you impose upon him when you deny the plain teaching of the Church that regeneration normally occurs at Baptism, but that the unregenerate are able to seek out God by the working of grace on their souls - else there would be no Catechumens.
And else St. Augustine would not have blessed the unbaptized Catechumens he was teaching who were seeking out His face: "God regenerate you!" (St. Augustine, Sermon on the Creed to the Catechumens, 17)
One cannot be both regenerated and unregenerated at the same time.
No sensible Christian has any reason to hold a strange new doctrine not ever heard of until 1500 years after Christ rose from the dead.
Where in Acts 10 do you find this idea that Cornelius was unregenerate? There's nothing in the chapter which suggests such an idea. Oh, right... you have to believe that Cornelius was unregenerate, because you believe in Baptismal Regeneration, and Cornelius was not yet baptized.
Well, that just goes to show how Romish Error can interfere with your personal understanding of perspicuous Scripture. There is no more evidence in Acts 10 that Cornelius was unregenerate than there is evidence that Noah or Abraham or Moses or Jonah's Repentant Ninevities were unregenerate, or for that matter the Believing Jews and Gentiles who died during Christ's earthly ministry but prior to His crucifixion and resurrection.
Now, it is true that, the Promised Messiah having come, it was fitting that those who had Faith in the Promises of God should be informed of the fulfillment of God's Promise; and God used Cornelius as a demonstration of the fact that this Good News should proceed also to the Gentiles; but the notion that Cornelius, whom Scripture calls a "devout" and "God-fearing" man in Acts 10:2, was Hell-bound prior to receiving the information that the God in whom he already trusted had indeed fulfilled His messianic promises... frankly, that's just silly. But that's where Romish error will take you.
One cannot be both regenerated and unregenerated at the same time.
Well, you've got that much right. That's an important point for you to comprehend. And that is something upon which I can build.
Now when you realize that the Old Testament Saints were regenerated prior to Baptism, you'll likewise realize that Cornelius was regenerated prior to Baptism, and the next thing you know, you'll realize that Baptismal Regeneration is a Biblically-unsound notion, and pretty soon... why, you're making progress, Hermann!! We'll make a Bible-believing Protestant of you yet.
No sensible Christian has any reason to hold a strange new doctrine not ever heard of until 1500 years after Christ rose from the dead.
Precisely correct, which is why we reject the AD 1564 Council of Trent. And given that you correctly say, "One cannot be both regenerated and unregenerated at the same time", it is my fond hope that, by God's grace, you will too.