The first clear use in the meaning “abode of the blessed dead” is in the New Testament (Luke 23:43 and 2 Cor. 12:4), so it is not a “Greek” (pagan) concept, but presumably a usage that originated among Hellenized Jews.
Biblical Judaism knew the concept of a primordial “Garden of Eden” but not of a future “Abode of the Blessed”. The latter occurs in Greek tradition (“Isles of the Blessed”, “Elysian Fields”) and may have influenced Jewish beliefs about the afterlife during the Hellenistic period.
A number of NT concepts such as moral perfection, God-likeness, eternal life, paradise and hell, tripartite division of man (body-soul-spirit), etc., are definitely Hellenistic, as are Greek terms like “Hades” (at Mat 11:23 and Luke 16:23) and “Tartarus” (at 2 Peter 2:4).
Hades (ᾍδης) was the general term for the underworld where all dead went and Tartarus (Τάρταρος) that part of Hades where the wicked were sent for punishment following divine judgement (cf. Plato,
Phaedo 111c ff). So, Paradise would have been the opposite of Tartarus and hence the “Abode of the Blessed” proper.
Greek
paradeisos in the original sense as introduced by Xenophon meant the royal park of the Persian king, the main features of which were trees and water, given that such parks were often set in an otherwise barren landscape (Plutarch
, Artaxerxes 25) as well as animals (for hunting).
The Abode of the Blessed of Greek tradition was described as a sunlit, fragrant place abounding in shady trees watered by pure streams and surrounded by meadows, with honey-sweet fruit and golden blossoms, where the blessed enjoy musical and other pleasant pastimes:
Hesiod
, Works and Days 156 ff; Pindar
, Olympian Ode 2. 57 ff;
Dirges Fragment 129, etc.
And, of course, in the wake of Alexander’s conquest of the Persian Empire even royal parks or gardens would have been Hellenistic rather than Persian.
Greek
paradeisos in the first century AD (when used in the context of afterlife) would probably have evoked as much the biblical Garden of Eden as the gardenlike Blessed Isles of the Greeks - depending on the audience. Proclus later uses
paradeisos in the latter sense (
Commentary on Hesiod’s Works and Days 169).