Hi Della!
One of the reasons the Church has been able to come to understand the threefold manifestation of the “one baptism” that we confess is, again, thanks to Augustine:
“That the place of baptism is sometimes supplied by martyrdom is supported by an argument by no means trivial, which the blessed Cyprian adduces from the thief, to whom, though he was not baptized, it was yet said, ‘To-day shall thou be with me in Paradise.’ On considering which, again and again, I find that not only martyrdom for the sake of Christ may supply what was wanting of baptism, but also faith and conversion of heart, if recourse may not be had to the celebration of the mystery of baptism for want of time. For neither was that thief crucified for the name of Christ, but as the reward of his own deeds; nor did he suffer because he believed, but he believed while suffering. It was shown, therefore, in the case of that thief, how great is the power, even without the visible sacrament of baptism, of what the apostle says, ‘With the heart man believeth unto righteousness, and with the mouth confession is made unto salvation.’ But the want is supplied invisibly only when the administration of baptism is prevented, not by contempt for religion, but by the necessity of the moment” (
On Baptism, Against the Donatists, Bk. 4, Ch. 22).
“Whatever you will and canst not, for done God does count it” (
Exposition on Psalm 58).
“[W]hen we read that certain ones in the Body of Christ, which is the Church, belong to the kingdom of heaven, we must understand that this applies only to the baptized, unless it happens that the pressure of persecution has come upon those who refused to deny Christ and they have been put to death before they were baptized, in which case the shedding of their blood substitutes for baptism” (
Letter 265).
You seem to want to assert that the thief was not already baptized, but Augustine’s point remains: although you are free to believe this, you cannot prove it.

And as you can see, Augustine had previously held the same view.
I also want to clarify that it is not true that a person is saved just because they hope to be saved. We need to be united with Christ by the grace of God through faith, hope, and love to be saved.
Your brother in Christ,
Pete